Many scientists see fusion as the future of energy | Hacker News Reader

Many scientists see fusion as the future of energy

nationalgeographic.co.uk

167 pointshhs388 comments

Commercial profitable nuclear fusion is a maybe by the end of the century. We really need to get nuclear fission capacity built out ASAP if we're serious about global warming and the overall health of the planet. Renewables just won't get us there.

Moreover, we need to overbuild the amount of clean energy produced to the point where we can waste it on energy inefficient processes for carbon recapture that we know work. Fusion is important in terms of helping this to continue to scale / make it even more economical / reduce nuclear waste and weapons concerns. Ultimately though, it's an iterative step over fission for the problems the most urgent ecological problems the world is facing.

EDIT: Did some back of the envelope math. Nuclear energy is worst case ~ $200 USD / MWh. At 2,400 kWh/tCO2 for direct air capture, that's $14 trillion USD or ~16% of the world's GDP that would instantly get us to net 0 yearly emissions. We'd need to invest more than that to start reducing carbon levels. This wouldn't recover things since damage is already done in many places (e.g. coral reef deaths) but it would arrest the worsening of issues. Additionally, this has knock on effects that improves the economy overall (weaker storms = less money recovering from disasters).

Do you have any concept of how far away the end of the century is? That's 80 years. Think back to 1942.

It's ridiculously arrogant to make predictions like this.

The most optimistic estimates by the commercial companies working in this space is the first commercial reactors coming online around ~2050. It takes time to build these reactors and integrate them into the existing power systems. I may have misstated my position which is that I don't think fusion will make up any meaningful part of power by the end of the century. The reason is a) requires fundamental engineering and materials breakthroughs b) funding for it is a pitiful amount compared to what it probably needs c) it's competing with other cheaper energy sources d) we don't have any net positive energy reactors yet.

The basis of that prediction is just looking at how long it took fission to take off and there it was being driven by military needs (submarines) and not civilian.

> and there it was being driven by military needs (submarines) and not civilian.

I'm surprised that support for fusion isn't part of US DoD policy; abundant, cheap, clean energy would be a huge military asset. Those explosives zooming back and forth in Ukraine are really just energy balls.

The necessarily super-expensive fusion would be a strict liability. It will, in consequence, not be built. All work toward that is pure waste.

The DoD does spend a great deal of our tax money on fusion, but not for "abundant cheap clean energy". It is, rather, for uses like what is occurring in Ukraine: death and destruction; and for vaporizing cities and ports, distributing radioactive fallout over wide areas.

Fusion would in no possible world be cheap. Whatever else they would be, fusion reactors will be the most expensive structures per unit of volume built by man.

Well, I guess I was talking about running costs.

Pardon me if I'm talking out of my ass, but this is what I tought:

* The main input to a fusion reactor is electrical power.

* The main output of a fusion reactor is even more power.

So that seems to me to mean that once you've incurred the capital cost, the machine produces free energy. My reasoning sounds naive and simplistic, because I don't know what I'm talking about. But what's wrong with my reasoning?

1. A fusion plant would be extremely expensive to build. The most optimistic estimates are 10x per GW vs. fission. But we really don't know how to build one; nobody has identified a material that would work.

2. It is extremely expensive to operate. The most optimistic estimates are >10x fission. A thousand tons of lithium "blanket" would have to be sifted daily to get a few grams of tritium for the next day's operation. Nobody knows how this could be done.

3. It destroys itself with neutron irradiation in only a few years. At best, major parts of the structure would have to be replaced using robots because of the extreme radiation in the parts being replaced. Similarly, for repairs. Nobody has built such robots, so they are custom one-offs.

The fuel cost of fission is a negligible part of its cost. The fuel cost of a fusion plant would be negligible, assuming enough tritium could be obtained at all. The ITER project expects to run out and does not know where they will get enough for future experimentation.

Nothing about fusion is free, or even affordable.

You could say it for 800 A.D. or 1200 A.D. too, and yet 880 A.D or 1280 A.D. wouldn't look too different. In fact, you could say it for 300 B.C. and 1300 A.D. - a whole millenium away - would still be quite similar technologically.

Not all periods have 1942-2022 amount of innovation. In fact 1942-2022 is itself bimodal and front-loaded. By 1980 already most major innovation had already happened. The rest is mostly efficiency improvements and diminishing returns, but much much much less major inventions.

in 1942 there were no nuclear (fission) power plants, yet today there is probably one within driving distance of your house.

additionally there are natural fission nuclear reactors that have been going for possibly billions of years... and one big fusion one within visual range :)

There are no natural fission reactors operating on Earth, and have not been any for billions of years.

Hmm... I guess after thousands of years they've all gone green and shut down :)

https://en.wikipedia.org/wiki/Natural_nuclear_fission_reacto...

Millions.

It's not arrogant at all, it's a rational, evidence-based prediction.

I recommend https://thebulletin.org/2018/02/iter-is-a-showcase-for-the-d... for an initial introduction to why the idea of fusion by the end of the century is only a "maybe".

As a sort of representative summary of the situation, the ITER project has been in progress since 1988 - 34 years - and hasn't yet achieved fusion for more than about 5 seconds.

On top of that, by design, it will never be net energy positive - the tens of billions of dollars and decades spent on it are purely to produce a proof of concept for sustaining a fusion reaction. Turning that into something that can actually act as a source of energy is currently still at the "unsolved problem" stage. We can't even write a project plan for how a viable reactor could be developed, because we simply don't know.

As such, there's no realistic scenario in which this situation somehow turns into viable fusion power before the end of the century, short of an unexpected major breakthrough. While such a breakthrough is conceivable, it's not something you can base a strategy on. The responsible position is to recognize that we can't rely on anything useful happening in fusion in this century.

One other point about the "think back to 1942" comment is that extrapolation only works when you have relevant data points to extrapolate. The technological advances since 1942 have been nothing like the advances needed to exploit fusion.

Fusion involves literally recreating the conditions in the heart of a star, but without the enormous mass of a star to provide the necessary pressure. There's no precedent for this in our technological history. Nuclear fission was trivial by comparison - nature does all the real work, all you have to do is arrange the fissile material appropriately. That's not the case for fusion.

It's an incredible achievement that we can produce a fusion reaction for 5 seconds, but there's no guarantee that we're going to be able to turn this into something that can be sustained day in, day out, and that generates more energy than it consumes.

>I recommend https://thebulletin.org/2018/02/iter-is-a-showcase-for-the-d... for an initial introduction to why the idea of fusion by the end of the century is only a "maybe".

Sure, if you acknowledge that fusion in twenty years is also a "maybe". If you can't, then you're not handling your probability distributions properly.

I've seen the scenario you describe as the "fission bridge to fusion" scenario, and as I understand it, a major problem is that it can't be done with existing pressurized light-water reactors. These systems just don't use Uranium very efficiently, they extract a small percentage of the energy from the fuel, and then need to be refueled.

This doesn't mean the "fission bridge to fusion" is impossible by any means, but it does mean that significant work needs to be done in developing and commercializing next-generation fission reactors, including breeder reactors, which use much more of the available energy from fuel, and possibly novel reactor designs that can run on reprocessed fuel from LWRs.

A political complication is that large-scale commercial nuclear fuel reprocessing represents a nuclear-weapons proliferation risk, and so might imply regulatory burdens, or require international agreements on use and control before it can go forward.

Refs: Dim recollection from reading Walter C. Patterson's "Nuclear Power", and some discussion about peak Uranium (https://en.wikipedia.org/wiki/Peak_uranium).

My understanding is that breeder reactors are politically problematic because of proliferation concerns.

Reprocessing increases net efficiency considerably [1]. Few people do it since uranium is very cheap relative to the amount of energy extracted from it, even without reprocessing. But if fuel ever becomes constrained, reprocessing would become competitive.

Nuclear weapons proliferation isn't a risk among most countries that have nuclear generation programs. Heck, most of them already have nuclear weapons. The rest can contract out reprocessing to nuclear-armed countries.

1. https://en.wikipedia.org/wiki/Nuclear_reprocessing

Also there are "near-breeder" CANDU heavy water moderated reactors: they are a proven technology that exists today and can use non-enriched uranium. They also in theory can use a plutonium/thorium mixture, so can burn thorium.

They are cheaper as far as fuel, but it turns out that fuel didn't become as expensive as anticipated in the 1970s (when it was thought that there would be 1000s of reactors). They are physically larger, so have a higher construction cost that put them at a disadvantage compared to conventional LWRs.

The tritium needed for fusion reactors comes from these CANDU reactors (some of the deuterium from the heavy water is converted to tritium, it is collected).

Peak uranium isn’t a thing even using today’s inefficient reactors.

The key insight is that if you’re using fission to power DAC, then you don’t even need to worry about proliferation. Countries can continue to use coal and oil while nuclear fission is used for DAC. An international agreement that they pay a tax to the countries that do have the capability to do DAC powered by fission. China and USA make up the vast majority of emissions, make up a good chunk of global GDP and both have nuclear power plant capabilities & they're not the only two countries who have that. Yes, there’s an imbalance there to think through but it can be remediated a bit (and mostly it’ll be Brazil and India that we would need to worry about assuming we can get China on board). Certainly better than doing nothing for decades or even a century.

I'm asking because I'm definitely not an expert on this, but if we can't use uranium efficiently, wouldn't that mean the plants would be creating lots of waste they wouldn't if they were more efficient? Would plants that would already be built be upgradable in the case more efficient methods of using uranium come online?

You can reprocess “waste” in a breeder reactor. Not sure if plants can be retrofitted with a new generation of reactor, but even if you need a new plant that’s not that big a deal because the waste is still usable fuel (it’s not a use once thing)

Trouble is, breeder reactors cost more than both types of water reactors for which we already can't find investors.

Because all the cost must be paid upfront, and takes 10+ years before the first GWh gets out. So, it does not fit well with private investors.

The cost of the electricity exiting a nuclear reactor is directly related to the cost of money (interest) to build the reactor. The reason is because it is cheap to run the reactor once built.

So, the cheaper the money is the cheaper the electricity is.

That is why it is not interesting for private investors.

It has to be financed by state to minimize the final cost if electricity at the end.

> The reason is because it is cheap to run the reactor once built.

Though nuclear plant operating costs have come down considerably since peak in 2012, the same is true of wind and especially for solar, still leaving nuclear power's operating cost per megawatt-hour above that of wind and solar. Though nuclear has the advantage of consistent power gen regardless of weather or time of day, it also requires $9B (far lower today) in construction costs and at least 5 years to get running, assuming no delays, while materials and installation of solar or wind is a fraction of that cost, and can be producing power in 6 months to a year. Nuclear energy not only requires engineers from a shrinking field, but heavy security, which will prevent operating costs from dropping much lower even if Uranium suddenly becomes cheap, which can't happen. A nuclear plant will require about 27 tonnes of Uranium at an average cost of about $47/lb., about $2.7B in Uranium alone.

There must be a way to make nuclear power plants cheaper without sacrificing safety.

Despite the large upfront cost, nuclear still provides cheap electricity. Currently, the price of the electricity generated by nuclear is more impacted by the way the upfront cost was financed than by the price of the combustible (uranium). You can see the difference between the electricity price for a UK nuclear power plant (private investors), vs. a French power plant (state investor). The private investors request 10% interest. The state investor request few percents. On a ~$10B tab it makes a difference and for a long time.

If we get serious about nuclear, we could find a way to build it a bit cheaper, and even faster (and with interests that would make it cheaper).

There might be also an argument to make, that nuclear might be too safe for its own good, and we could relax the safety measure. Not trolling here. Given the number of death due to nuclear power plants (near zero) are we too cautious at the expense of its deployment. I suspect that relaxing the safety rules is what some governments might have to decide if the fossil energy becomes just too expensive, they could stretch and extend the life span of the reactors beyond what was previously deemed safe.

And the population should be informed about the real risk of nuclear...

Nuclear has an underserved extremely bad reputation (maybe due to the bomb A/H, or how media reported on Tchernobyl/Fukushima ?). Earth had natural nuclear reactor that have been running for thousands of years (https://en.wikipedia.org/wiki/Oklo_Mine), and nature littered the waste everywhere. On the other hand, we carefully confined our nuclear reactions, and store properly waste (in most countries everything exiting a nuclear facility is considered nuclear waste, even though there is no trace of radioactivity whatsoever).

We probably poison general population way more with chemicals and yet the general population does not seem too worry to have chemical factories all around. Silicon Valley dear Palo Alto is a superfund (https://cumulis.epa.gov/supercpad/SiteProfiles/index.cfm?fus...). Did we abandon the site ? No, we excavated and off-site disposed of approximately 10,700 cubic yards of soil, ventilated all the buildings so you do not smell the Palo Alto cookie dough (http://www.aarongreenspan.com/writing/20130404/in-search-of-...). And no one is batting an eye. The groundwater is contaminated and yet the real estate is a premium to raise a family.

We have 12,000 people dying in stairs every year in the world (https://www.medlegal360.com/fall-down-the-stairs/), and yet we have nowhere near the same safety measures for those evil stairs that keep killing every year. Is it due to the powerful lobby of the carpenter's guilds? No, we are just careful when going down the stairs.

We have very different risk tolerance with radioactivity. Probably because we cannot "see" it with our senses. We are wired to fear what we can grasp with our senses. I will still go down the stairs recklessly, unless maybe I actually witnessed someone die in a stair. Yet there are radiations everywhere, some of us are more exposed than other. And our body is engineered to deal with it, to a certain degree. For instance, according to IAEA: "The individual dose limit for radiation workers averaged over 5 years is 100 mSv, and for members of the general public, is 1 mSv per year." (https://www.iaea.org/Publications/Factsheets/English/radlife). Yet we let flight attendants flying without any radiation monitoring, even though they are technically "radiation workers" with some even likely passing the recommended 20 mSv/yr limit.

Getting radiation and breaking our DNA is part of life. Life on earth from the beginning had to put in the specs a way to repair, as we have been and still are attacked by radiation and oxidation all the time. Our body due to oxidation alone breaks hundred of thousands of cells every day. A major part of our DNA is solely responsible to repair it. And yes, sometimes it fails (cancer). But getting radiation (dentist, flights, etc.) are considered fine, as long as you do not do it too often.

A well run nuclear reactor should not be more worrisome than a well run chemical plant.

Let's build some good (breeder) nuclear reactors !

Once the uranium cartridge is depleted after several years, that becomes waste. There are mostly 2 ways to deals with it:

1. Like US or Sweden, you take it as-is and bury it. 2. Like France and Japan, you recycle it to make more cartridges. France has a dedicated facility for it, Japan used to send its waste to France for recycling.

If you supply the world's primary energy demand (about 18 TW) with LWRs, the global uranium resource (not reserve) runs out in about five years.

Global supply or global mineable resources?

Global resource.

'A resource is that amount of a geologic commodity that exists in both discovered and undiscovered deposits—by definition, then, a “best guess.” Reserves are that subgroup of a resource that have been discovered, have a known size, and can be extracted at a profit'

https://www.cliffsnotes.com/study-guides/geology/earth-resou...

This is hypothetical, as it cannot happen. Building nuclear reactors to replace 100% of energy production would take ages on its own.

And if the plan is to build lots of nuclear reactors, it would better to build breeders and not old LWR.

Nuclear is great as baseload, but it is more expensive than wind/solar when you just look at pure generation without storage. So we definitely need to get nuclear built out, but you want as much cheap renewables as you can get the grid to support, and as little expensive nuclear as possible.

And it's not what you would use for CO2 capture. For that you would use renewables, because it doesn't matter what time of the day you do it, or for how long you do it continuously. So just direct excess renewable power into CO2 capture.

The problem with renewables is one of space and materials rather than energy production. Nuclear is drastically smaller in terms of the land footprint.

Focusing on cost is misleading because the costs are because we haven’t invested in fission in many decades / regulations are fairly insane. For example, the cost argument would go the other way in the 90s when wind and solar were much more expensive. Also, solar provide energy when there’s typically peak demand so you can’t really load shift for DAC. Wind you might be able to do that.

There is in fact no problem of "footprint" of renewables for nukes to pretend to solve.

https://www.bloomberg.com/graphics/2021-energy-land-use-econ...

It seems like you need a fair amount of land devoted to wind or solar to go carbon neutral. Presumably much of this is dual use?

It could all be dual use. There is no need for any of it not to be.

If you have some ground you are not using for anything else, and is convenient to a grid tie-in, it is harmless to just put solar on that. I can't see that as using up land.

Yesterday I watched a video about the commercially available options for installing an electric power generation plant on the balcony of your rented apartment. Commercially available, now.

More seriously, off-shore wind takes up virtually no land, and on-shore wind and PV can share land use with pasture, feed crops and horticultural crops. PV actually improves crop yields in dry regions because of the shading and reduced stress on the plants. So in some places it has a negative footprint. Storage uses no more land than peaker gas, and probably less when pipeline right-of-ways are counted.

There really is not a land footprint problem.

It’s about MWh per sq ft. Renewables have terrible energy production density compared with nuclear. Off shore wind isn’t really a thing and the secondary benefits are irrelevant - nothing is stopping you from using a basic shade structure / solar panels if you really want the power anyway.

What matters isn't power density, it's cost, and renewables are handily beating nuclear on that, the relevant metric.

I would pay more to not cover everything in toxic crap.

PV is toxic crap? What?

They have lead, etc. In them. If not properly recycled (they won't be) that'll end up in the environment. And they cover up and mar the beauty of the land. Maybe that's fine if you live next to a desert.

There are lead backing sheets being used with PV, but they aren't required, and are being phased out in Europe and some other places. The lead is incompatible with some PV new higher efficiency silicon PV technologies due to processing temperature, so there's additional reason to get rid of it. Bifacial PV cells would not have a backing sheet. In any case it is not a requirement for even monofacial PV.

There's no problem there. Look at how much energy just rooftop solar in residential areas is capable of producing. You can also put wind turbines in the ocean and pipe the energy to land.

There's plenty of space - deserts of the southwest for solar plus offshore wind could easily suffice to produce all of the power needed in the US by themselves. The issue is lack of grid transmission infrastructure, which is a reliability issue during times of extreme weather independent of whether it's a renewables based grid or not. As for materials, there are some rare earth metals that are used in some solar panels, but many others don't require them. If market conditions dictated, use of those materials would shift on it's own.

No solar panels use rare earth metals. I wish this falsehood would stop being repeated.

You're right! Thanks for the correction. Thin film modules use Cadmium Telluride, which includes two rare metals* (not rare earth* metals). I want to note that there are some similar supply concerns with each of those rare metals. But in any case, my larger point is that thin film modules represent less than 10% of the market, and are in no way critical to solar's success.

> The problem with renewables is one of space and materials rather than energy production. Nuclear is drastically smaller in terms of the land footprint.

If you can't argue cost, make up some other argument. Land use is generally not an issue for solar or wind, because you can dual use. You can make the calculation that putting solar on roofs and parking lots would be much more area than needed to power the whole of the US.

> Focusing on cost is misleading because the costs are because we haven’t invested in fission in many decades

Actually nuclear has received significantly more subsidies than renewables [1, 2, 3]

[1] https://www.thinkgeoenergy.com/wp-content/uploads/2011/10/US...

[2] https://taxpayer.net/energy-natural-resources/understanding-...

[3] https://commons.m.wikimedia.org/wiki/File:Too_much_money_for...

> / regulations are fairly insane.

Actually, for the size of the projects wind and solar have significantly higher regulatory hurdles. [4]

[4] https://www.ft.com/content/19d502c7-c1f7-4b07-9ad6-67f110507...

> For example, the cost argument would go the other way in the 90s when wind and solar were much more expensive.

Yes and guess what all the nuclear proponents said? Don't invest in renewables. However, there is a fundamental difference wind and solar (solar more so) are on exponential price reduction curves and there is currently no indication it will stop. Nuclear on the other hand is not (prices have actually increased in many places) and there is nothing indicating that this will change.

> Also, solar provide energy when there’s typically peak demand so you can’t really load shift for DAC. Wind you might be able to do that.

How about we first transition to using carbon free energy production first before DAC. It does not make sense to produce energy using fossils (with the inherent efficiency losses) and then use another inherintly inefficient process to capture the carbon. You need much less energy if you move the first process to carbon free.

> because it doesn't matter what time of the day you do it, or for how long you do it continuously. So just direct excess renewable power into CO2 capture.

Assuming those CO2 capture plants are run on some sort of pay for service basis, there will be an incentive to keep them up and running. The owners won't want their fixed capital to sit idle.

Nuclear takes way, way too long to get online to help with global warming.

Renewables absolutely can and are "getting us there." It's a solved problem.

Fusion is always some long period of time away. It is not close to being a viable source of power, and there are convincing arguments it never will be.

And regardless, why do we need to waste so much money trying to turn into a viable source of power when we have solar and wind now and they are cheaper than any other form of power?

By all means keep researching fusion for scientific reasons, but enough with the empty promises about it being the ultimate power source. And fission can die off as the existing reactors reach the end of their lives. It is too expensive, too environmentally dangerous and totally unnecessary.

Renewables are a solved problem, but storage of energy to combat the unreliability of renewables isn't.

NPP's take about 7 years to build. The latest EPR builds are taking more due to an over complicated design.

Storage is not, in fact, a problem. Numerous methods using century-old tech are cheap and practical, and only need to be built out.

They are not being built out yet because there is not excess renewable generating capacity to charge them from.

Renewables have yet to demonstrate the ability to replace fossil fuels in any meaningful way. They seem to top out at 10-20% of the energy mix. France achieved net 0 many decades ago because they went all in with nuclear whereas their neighbors that went with renewables haven’t gotten anywhere close to that.

The best time to plant a tree is 20 years ago. The second best time is now.

France hasn’t achieved net 0, not even close. And there are several countries with more than 20% renewable energy in their grid.

I agree with the first part but not the second. Up until recently (when a lot of their nuclear went offline) they were one of the lowest emitters in Europe. They were comparable to Sweden and Iceland, which have substantially smaller (and more centralized) populations. I'll agree that thinking nuclear will get us all the way to net zero energy emissions is silly, but let's not undermine the great accomplishments France has made. They have been leagues ahead of the rest of Europe. Even at significantly reduced capacity they are still one of the lowest emitters.

https://app.electricitymaps.com/zone/FI

And even those countries in the EU such as Denmark rely on France for electricity imports because no country in the world has any large scale storage solution for renewables.

It would be stupid to put money into storage before there is excess renewable capacity to charge it from. So, people instead put money into generating capacity.

When we have any use for storage, we will build out storage.

France imports large amounts of energy during winter, largely from gas and coal producing neighbors.

Renewables have long since demonstrated ability to replace fossil fuels, and are being built out at an always increasing rate, already exceeding 20% in many places.

France is importing power.

This is plain wrong. France has been one of the most reliable exporters of electricity in EU for over a decade https://en.m.wikipedia.org/wiki/Electricity_sector_in_France...

Some of the time. Not this summer, e.g.

> Renewables have yet to demonstrate the ability to replace fossil fuels in any meaningful way. They seem to top out at 10-20% of the energy mix.

Denmark has reportedly reached 53.3% of electricity consumption with wind and solar.

"The first half of 2022 has been a record-breaking period for green energy production in Denmark. Danish windmills and solar panels produced 10,9 TWh in the first six months of the year – a significant 12% increase from the previous record from 2020. Another all-time high, the fraction of wind and solar power in the total electricity consumption was 53,3%."

https://stateofgreen.com/en/news/green-danish-energy-product...

> France achieved net 0 many decades ago because they went all in with nuclear whereas their neighbors that went with renewables haven’t gotten anywhere close to that.

Unfortunately even France no longer seems able to build new nuclear generation capacity at a reasonable cost. While wind, solar, and batteries get ever cheaper, nuclear has gotten more expensive over time.

For what it's worth I used to agree with you that Nuclear seemed the only viable way forward, after reading https://www.withouthotair.com. However much has changed over the past 14 years since it was published.

Denmark reached 100% wind capacity in 2013, 9 years ago, and is today completely dependent on Norway and Sweden to supply hydro energy when demand exceed supply. Around 50% of the energy Denmark consume is from imports.

Denmark wind and solar farms do sell a lot of energy to other countries when the weather is optimal, but when its not they have to buy that energy from somewhere. EU ruled a while back that the Swedish energy grid must sell energy to Denmark if there is available energy, and so the Swedish grid and the Danish grid is thus tied in a way that removes any distinctions between the two.

Denmark is thus a terrible example of wind replacing fossil fuels, unless they suddenly would forgo imports and live with only having power 50% of the time. They are a great example of how you can invest in renewable energy as long the issue of grid stability can be solved through imports.

Denmark sounds like a big success story. You've got half of locally consumed energy being generated locally from wind and solar, and you're also sending renewable energy to other countries which reduces the amount of fossil fuel they have to burn.

They should build even more so they can send even more and have an even bigger impact. And if their neighbors did the same thing and sent excess capacity to each other, then it'd all net off to not needing much storage at all. Maybe 10 percent of supply needs to be met with gas peaker plants when variability gets really bad, prior to storage solutions becoming cost effective.

So this case study of Denmark shows there is little substance to the criticisms of renewables.

With about 50% average effectiveness, overcapacity is fairly simple to calculate. With 100% capacity you get what we have today, ie around 50% from renewables and 50% from imports. At 200% capacity you get 75% from renewables, 25% from imports. at 400% capacity you get 87.5% from renewables, 12.5% from imports. At 800% capacity you get 93.75% from renewables, 6.25% from imports. at 1600% capacity its 96.875% from renewables, 3.125% from imports (assuming that renewables can scale down to that low weather conditions).

Obviously, running at high overcapacity results in significant less profits unless you can sell the overcapacity to other countries. When Denmark hit 100% wind capacity the growth of new wind halted dramatically down to basically the same as consumption growth. There is a limit on how much you can dump, i mean export, to other countries before there is no one willing to buy excess energy during periods of optimal weather conditions.

This isn't the scaling law we'd see.

Firstly, Denmark's renewables are largely wind. But wind and solar are negatively correlated. As they add more solar, the variability will cancel out.

Secondly, variability is heterogeneous across geography. You're not building the second wind turbine in the same location as the first. As you connect countries up, or as you build in locations that don't currently have it, the variability cancels out.

Denmark is tiny. If the EU takes it up as a project, significant amounts of variability cancelling will happen, as you mix offshore wind, onshore wind, and solar, across the continent.

So, > 80% of EU's energy, from wind and solar, without any storage, should be achievable.

> running at high overcapacity results in significant less profits

Still better economics than nuclear. Even if you're at 3x overcapacity, it's still cheaper[1]. Not to mention you can sell most of that overcapacity (even to countries outside the EU) and get the money back, or convert it into green hydrogen and sell that.

[1] https://ourworldindata.org/cheap-renewables-growth

Well, Denmark is tiny so if its not windy in one location then its unlikely to be very windy in an other. Same for the sun.

EU has however already taken it up as a project. It is called the European energy grid, which as I describe above forces countries to sell to each other. There is an economical limit to this from transit and transport costs, but in concept the whole union is already a single grid connected from the southern part of Italy to the polar circle in northern Sweden and Finland.

Denmark consumes around 33 Terawatt of electricity. They import 20 Terawatt. They also sell about 14 Terawatt of renewable energy. Sweden (hydro + nuclear), Norway (hydro), and Germany (coal, gas) are the main players that provide those 20 terawatt of electricity to Denmark.

This far up north the sun doesn't cancel out the still periods of wind. Demand for heating during winter far exceeds the few hours of sun that you get.

Green hydrogen, as nice as it is for reducing the emissions from steel industries, still costs about 10x of nuclear if you use that green hydrogen to produce power. There is a big economical reason why no one is doing that at this point in time. Estimates from researchers in the field varies from around 2035 to 2055 before we will have our first commercial green hydrogen power plant in operation. Still green hydrogen would be a nice way to recover costs if Denmark did decide to go for 300% overcapacity, but they would still need to heavily depend on Sweden, Norway and Germany to provide the electricity when demand exceeds supply. Their own grid will not suffice.

Why doesn't solar cancel wind far up north like it does elsewhere? The sun shines longer in the summer, and it's less windy in the summer.

  "Well, Denmark is tiny so if its not windy in one location then its unlikely to be very windy in an other. Same for the sun."

That's true to a large extent for Denmark, but untrue to a large extent for the EU or larger countries. That's why I said that the EU can get over 80 percent of its energy just from renewables without storage, for a cost significantly cheaper than nuclear.

There are of course windy days where wind generates more electricity than is consumed, but the 53% figure is for the first half of the year.

The U.K. is up to around 40% of annual electricity consumption from renewables too. (43% of generation which I think excludes the 8% from imports.)

Net Zero is a good target but ultimately it’s getting most of the way there which is important. We need to replace heating, transport and industrial uses so we have to build out as much emissions free generation capacity as we can as quickly as we can. Renewables currently seem like the most cost effective approach.

Renewables obviously enable us to mostly stop using fossil fuels, fossils have just been too cheap because of unpriced externalities. (replace is the wrong word because some of the fossils use can and should just be stopped and not replaced by other energy)

There isn't anything mysterious we expect to empirically discover through demonstrations approaching 100%, though of course engineering does incrementally improve and progress.

Relevant: https://en.wikipedia.org/wiki/List_of_countries_by_renewable...

> Renewables have yet to demonstrate the ability to replace fossil fuels in any meaningful way. They seem to top out at 10-20% of the energy mix.

This is just utterly wrong.

In the UK 43% of power came from renewables in 2021: https://www.nationalgrid.com/stories/energy-explained/how-mu...

Even in California renewables are at 33%: https://www.energy.ca.gov/data-reports/energy-almanac/califo...

nearly 50% for Germany

https://www.tagesschau.de/wirtschaft/strom-erneuerbare-energ...

Renewables absolutely can and are "getting us there." It's a solved problem.

I hope that's true. So does that mean there's no need for the sweeping societal changes that prominent environmentalists are demanding because we'll be able to maintain our high-energy lifestyles with nearly 100% renewables?

I’m curious about facilities like the one in NJ that produce power by burning trash. I wonder how viable they would be on a larger scale.

> I’m curious about facilities like the one in NJ that produce power by burning trash. I wonder how viable they would be on a larger scale.

Incinerating already sequestered carbon via burning hydrocarbons is a path to nowhere. It’s a profitable business for sure, but so is mining coal.

Because of comments below, I want to piggyback here.

Climate is a pretty complicated topic that is often vastly overly simplified. To the point where major mistakes are made. Remember, first (and even second) order approximations are only useful in limited regimes.

If you're in the camp of "net negative, regardless of costs" then it is silly to ignore nuclear. But people seem to confuse this as "nuclear VS renewables." We should ABSOLUTELY build as much renewable energy as possible. The issue is that the world/country/states aren't homogeneous. For example, Southern California and the entire Southwest probably needs little to zero nuclear power. There's more than enough sun and wind year around to exceed demand. But this isn't true everywhere. Where this isn't true (and where there isn't hydro availability) nuclear is a great option and it is silly to discard it as an option. You also can't just transport energy across the country without significant losses and drawbacks (e.g.s energy security, reduced priority).

So I want to make it clear that you can think nuclear is expensive and too slow but still be in this camp. This camp is just believes that you shouldn't remove a zero carbon emitter from the table. Why tie a hand behind your back? You don't have to use that hand, but it may come in handy every once in awhile.

As to carbon capture, again this is a complicated topic. Often it is overly simplified into "plant more trees." But we just can't plant enough trees and the scientific consensus is that this won't get us there. There's also plenty of natural ways to reduce carbon. Land management is broad term usually used. But soil restoration, bogs, and swamps are far less sexy than forests (which when young are actually carbon emitters). DCC still has a long way to go too, but again, why turn away from it? Use every tool at hand. Especially because we have to remember that zero emissions typically means "zero energy emissions" and that doesn't solve the other half of the problem that we have.

I know everyone is passionate about this subject (I am too) but I also encourage everyone to recognize that we have more similarities and differences. We are mostly arguing about the most efficient way to reach the goal, but mind you that if we fight too much others can use this to divide us and make us overall less efficient. Complex problems require complex solutions. Very few people here are experts in climate and if you ever talk to climate scientists they will happily tell you that their expertise is limited to their niche. It is too complex of a problem for a singular person to understand. So let's keep that in mind when we're arguing with one another. It is good to have arguments and discussions, but turning into fights is unproductive and just demonstrates how naive we all are. I'll bastardize a Feynman quote: "I think I can safely say that no one understands Climate Change."

> ... forests (which when young are actually carbon emitters).

Can you expand a bit on that, since it doesn't match my understanding? Where does the carbon come from that young forests emit?

My understanding is:

A tree is a carbon sink, i.e. it captures carbon as long as it is growing (the carbon goes into its organic matter). Once it stops growing it has a constant amount of organic matter, a constant amount of carbon, and no net exchange of carbon. That is until it burns, or decomposes, or parts of it are eaten by animals, or whatever.

The same, but on a larger scale, goes for a forest, or any ecosystem really: when total organic matter increases carbon is captured from the atmosphere; when total organic matter decreases carbon is emitted.

Still to my understanding, young forests are forests that grow pretty rapidly and are therefore excellent in capturing carbon.

What am I missing?

A whole lot unfortunately, as the life is not a simple topic.

https://pubmed.ncbi.nlm.nih.gov/34542151/#&gid=article-figur...

How does that support the claim that young growing trees release more CO2 than they capture?

Not OP but planting a man-made forest is bound to require a lot of carbon up front; you’d need to transport people, plants, etc, to the forest-site, and would possibly need prepare the land for planting using machines (which again need to be transported, need logistics to transport fuel, etc)

I am not sure about the "a lot of carbon up front" part.

Compared to the industrial, man made carbon capture plants madness, the cost of transporting young trees, people and water would be nothing. The main "problem" with the forests approach is that some very important people won't be making huge money off of it.

Sure! I'm actually glad you asked, because this is a perfect example of first order thinking giving you the wrong answer. Your understanding is actually (almost) entirely correct! The problem is that a forest is an entire system, and not just the trees. Talk about missing the forest for the trees :)

So a singular tree grows more aggressively when young, but you also have to consider that the tree respires and that it drops matter to the ground which microbes decompose and respire CO2! But the overall system changes once a forests get larger and there is canopy closure. Once we consider the entire system (or at least more of the system) we reverse our conclusion and find that young forests are NET carbon sources (despite individual trees being carbon sinks) and that old growth forests are NET carbon sinks. PBS Terra does a good explanation of it so I'm linking it here[0].

Also, with that said, we should add some information about land management. After all, logging cycles and maintaining old growth forests is part of land management, but it is far from the whole picture. Forrest Fleisch (ironic name) frequently writes about this so I'll just leave one post here[1] and allow you to dig in more.

I hope this clears things up. I'm not an expert so I don't have all the answers myself. But this is what I've gathered from conservationists and those studying forests. And in all fairness, the prevailing theory was that of the first order until relatively recently when we could actually measure the entire system. So old information can be holding us back, but also I think this demonstrates that we as the public understanding can significantly lag that of the scientific consensus. While I agree we should challenge experts this also demonstrates the importance of relying on them.

[0] https://www.youtube.com/watch?v=LDdKOmvIKyg

[1] https://mobile.twitter.com/ForrestFleisch1/status/1306221445...

That twitter link talks about other complex effects, so let's focus on the PBS video. I'll have to find out more about the research, but just from the video things don't make sense.

If a young forest is a net carbon source, they question remains: where does that carbon come from? Was there carbon stored in the soil that is released? If not, the carbon balance doesn't make any sense. As with anything, change in mass over time equals flow rate in minus flow rate out. If biomass increases, stored carbon increases as well, so flow rate in is larger than flow rate out. That means we have a carbon sink.

I don't understand the research results for mature forests either. How can they be a carbon sink when the amount of biomass is constant?

Something doesn't add up. It could be my understanding of things. I'm going to try and find some time to delve deeper in the research.

Edit: it looks like the video mainly talks about disturbed forests, where trees are planted again to regrow the forest. It's not explicitly mentioned though, just silently assumed, and that creates lots of unnecessary confusion and misunderstanding. A disturbed forest likely still has relatively large amounts of biomass in the soil, that get released. That is not what I call a young forest though, which is what we were talking about here. A young forest doesn't have a lot of pre-existing biomass.

I'm sure there are examples of places where neither Wind, Solar nor Hydro is viable. But looking at the EU, it doesn't seem to be the case here and (without looking very deep into it) I'd expect that to transfer to the vast majority of the world. Especially with HVDC for continental-scale electricity transport and the introduction of grid-based storage in the form of P2G (or something else), it's possible to even things out. There are almost no countries which are deploying as much renewable energy as possible, even with current grid-tech. And then it does quickly become a "nuclear vs renewables" issue.

Looking around in the EU, many (often more to the right, as opposed to the greens that often occupy more the left side of the spectrum and tend to be anti-nuclear) don't particularly want renewables and see great potential in nuclear instead, using it to dismiss the "green crap". Countries that push more heavily for nuclear seem to neglect renewables and countries investing in renewables often care little for expanding nuclear.

The grid deployment & economic characteristics of nuclear & renewables (solar, wind, not hydro) also clash, with them not playing very nice with each other resulting in the need to throttle one or the other without any reduced costs. Both also need some sort of storage if they're the major electricity provider. France heavily depends on pumped hydro for this purpose.

Maintaining existing nuclear capacity is very reasonable, but looking at how old the reactors (in the EU and America) are means that it's likely we'll have to replace the majority in the next 10-20 years. France is already having major issues (partially due to age) [1] and isn't expanding renewables enough. It's investing billions in new nuclear plants instead, which (at least based on the last decades) are going to take much longer than planned, be much more expensive and will some of them will not be finished.

Thus I expect nuclear energy to play a very small role in 2050.

I think this take generalizes for most of Europe, North America and richer non-asian[2] countries. Poor countries are unlikely to build a lot of major nuclear capacity due to price issues and concerns from the major global players about security (combined with lower expectations for grid reliability and an expected slower phaseout of fossil-fuel power plants).

To your last paragraph: While it's true that this can be used to divide, inefficient solutions that are unlikely to work are also used as distractions from doing something (and giving the illusion of solving the problem). Looking at E-Fuels, which are getting pushed as a reason to continue selling conventional gas vehicles to the masses or "Clean Coal" (carbon capture at the coal plant) to continue operating coal plants unchanged. Focusing on banning single-use plastic bags as a green action (which does have benefits but does not reduce emissions in most cases) and buying ineffective carbon offsets to quickly "greenify" your company without investing much in reducing emissions. There are many "solutions" offered that won't help (serving as reason to not do more) and at least in part I see some advocacy of construction of new power plants "in the future"™ (when it's not my financial/political/hot topic issue anymore) as doing the same. Not all, many are genuine, but some.

[1]: https://jeromeaparis.substack.com/p/edfs-woes-are-a-bigger-l..., https://www.ft.com/content/0df04c06-83c0-4080-a68b-c00fd4bc4...

[2]: South Korea & China have seen less difficulties with building nuclear, but haven't been without. I don't know enough to say if these difficulties will lead to a major decline nuclear construction in combination with renewables are continually getting cheaper.

> Looking around in the EU

There's your problem. Europe doesn't generalize, and that's my entire point. Nowhere does. Europe benefits from warm winds. Often London is warmer than NYC despite being the significantly further north. The benefit here is lots of wind and far milder climates. It is the reason Europeans frequently don't have air conditioning (changing) but most Americans do. The US is warmer on average but also, generally, has larger seasonal swings in temperature. Hydro power is also notoriously non-homogeneous (especially considering environmental factor). For example, a significant part of the US (the part almost no one lives in) is a giant desert.

> Countries that push more heavily for nuclear seem to neglect renewables and countries investing in renewables often care little for expanding nuclear.

Can you give an example of such a country? France is one of the lowest emitters in Europe (even with current issues). France and Sweden draw significant amounts of power from hydro and nuclear. France, currently, is getting ~100gCo2eq/kWhr (and previously was <30) while Germany is 210. Britain is 180, Spain is 230, Portugal is 330, Italy is >300, and Poland is >500. If your concern is with France I believe you need to get your priorities straight. The majority of Europe emits multiples of times that of France and it has been this way for decades. So I'm not sure why you feel you need to pick on them. When the other countries are producing less (or even in the same ballpark) then we can talk.

My entire argument is that this heterogeneity makes the problem of choosing the right power source rather difficult. You can't just look up average (or median) prices and apply them unilaterally. Doing so comes off as extremely naive because, again, first order thinking is not helpful here. Complex problems require complex solutions.

And I need to make this absolutely and abundantly clear: I AM NOT SAYING NUCLEAR EVERYWHERE. I explicitly said we should build as much renewable as possible. I will not be upset if the total amount of nuclear power, globally, is zero. If you believe anything less, I think you gravely misread my comment. I think you may have missed this point and confused my being okay with nuclear as being a nuclear bro. So there really isn't much to argue with here (besides calling the kettle black) because I'm not nuclear gung-ho. Forgive me, but it is often frustrating that when I make the slightest argument in favor of nuclear I get responses as if I proposed a nuclear vs renewables argument. Again, I explicitly stated that this is not the case.

Nuclear is not a solution. You can't power energy-intensive industry with it; you'll be outcompeted by some other country where solar is cheap.

Would you mind reading what I've said instead of assuming a position? We have a good faith rule on HN and you're violating it.

I don't understand your argument. The EU is significantly smaller than the US and the US has much more climate variation across its area. Moreover integrating the EU energy grids is more difficult considering they are separate countries. Still it's happening and not due to government policies, but because it is good investment to connect e.g. Norway to Germany.

In the US it could be much easier to build an integrated grid. There have been many simulations that showed one could fulfil the US electricity needs based on renewables and overprovisioning alone. Any storage makes it actually cheaper.

I don't understand your argument tbh. Europe is roughly the same size as the US and is about twice as dense. The density means that power demand is significantly higher and you need more frequent generators. The increased sparsity and climate variation of the US makes it more difficult to build a grid all together. But both the US and EU have interconnected grids so I'm not sure what you're saying here.

No one was arguing against interconnected grids. I was arguing that you don't want to generate power in California and use that power in Maine. Maybe that's the issue? While this is possible, you not only are losing a lot of power in transit, Maine would be at serious risk for power outages. Both distance and climate variation play a role here as both these factors make it easier for a grid to go down. Let's say there is a 1% chance of outage per 100 miles of grid. Well you got about 2500 miles to cross.

Also, the US is federated. I'm not sure if the politics make it any easier than in Europe. In our example Maine is beholden to at least 10 states. If something happens you know those states are demanding they get power first. The federal government (president) isn't just a dictator who can make the states act uniformly and in the best interest of the country as a whole. It's really best to think of the US as somewhere between a country and the EU itself. It was set up to be more like the EU in the first place but power has consolidated over time.

> Can you give an example of such a country

Not sure what you want to say with your list, but Nuclear shares the low carbon aspects of renewables but is by definition not one.

This is the list of European countries looking to build nuclear power announced in the last few years:

- France

- Finland

- United Kingdom

- Poland

- Hungary

- Czech Republic

Of these countries only Finland is also strongly pushing renewables. The UK is a bit weird.

> So I'm not sure why you feel you need to pick on them.

Because France is failing bad on electricity policy. Their existing electricity system is mostly made up of old nuclear plants that are nearing their end of life and will get increasingly unreliable. It's not clear how France will replace them in a reasonable time frame with new nuclear power plants (long build times are a huge issue and to few are announced to replace the existing reactors), leading to it becoming a net-importer from net-exporter (we're already seeing this happening). This is one of the factors currently driving up electricity prices around Europe and will be a major strain on the European grid. Because most nuclear power plants are old around the western world, this a worrying not just for France which bet hard on nuclear and should be very glad that it did at the time.

There are also many other countries which are basically making little effort to move away from fossil fuels for electricity and that's worse for the environment (but better for the grid). But they're obviously doing the wrong thing in regards to climate. France is not obvious.

> Complex problems require complex solutions.

Yes. But the pricing behavior of nuclear plants compared to wind and solar is extremely similar, leading to similar issues and concern. Most of the cost is capex, little opex or marginal. This makes overbuilding unattractive, especially when the capex is very high as in nuclear leading to either requiring power plants with low capex, high marginal costs (like gas), expansion of storage (historically mostly in the form of hydro) or relying on an otherwise more diversified grid to even things out. And then it becomes much easier to compare pricing as compared to e.g. gas plants.

My impression is that often the broad strokes of policy are (while informed by deep analysis) more formed by political beliefs and motivations than careful analysis. When germany started to deploy solar & wind with the goal of making them a significant portion of the power grid, this was in hindsight a good move but not supported by the facts. Both were very expensive (with no expectation of them getting so cheap) and no grid operator thought that the grid could handle more than a few percent of renewables. The move away from nuclear from the 70s onwards was also very much based on public opinion & fears, not on quantifiable data on risks. The move toward nuclear before that was also born out of hopes for very cheap electricity ("too cheap to meter") that didn't really pan out as much as hoped.

> I AM NOT SAYING NUCLEAR EVERYWHERE.

I am reading your comment as saying it's not nuclear vs. renewables, both can work in some circumstances. And I believe that due to production characteristics on the power grid, it is a nuclear vs. renewables issue in the grid. Additionally, that countries are looking at nuclear options that are unlikely to work (keepin' an eye on the historical trend for construction) will downscale expansion of renewables (if you're planning for 30% nuclear, you don't need as much renewables) and thus lead to more fossil fuel capacity renaming in use.

It's not out of the question that smaller, more modular reactors built in a big factory somewhere might be able to improve things for nuclear power plants and make them reasonable options in terms of build times and costs, but I'm doubtful.

>So I want to make it clear that you can think nuclear is expensive and too slow but still be in this camp. This camp is just believes that you shouldn't remove a zero carbon emitter from the table. Why tie a hand behind your back? You don't have to use that hand, but it may come in handy every once in awhile.

I want this "hand tied behind our back" for 3 reasons:

* It inefficiently consumes public money earmarked for fighting climate change because it demands lavish subsidies.

* Nobody builds it because they give a damn about the climate. The government is keen on it exclusively coz it shares costs with the military industrial complex.

* They refuse to pay for > 0.1% of their own insurance while running massive PR campaigns telling the public how misinformed it is about the risks.

So yeah, as far as I am concerned it needs to die.

Plus...

* Humans are just not competent or trustworthy enough in general to run larger numbers of these plants safely in the long term. The excuses you hear when accidents, natural disasters, or wars happen are the point: we can't reliably guard against those scenarios, so we'd really just be committing to creating more and more Chernobyls and Fukushimas around the world as time goes on.

In fact all of your bullets are in a sense a consequence of this point: they're a result of people trying to maximize profit with a minimum level of care for the consequences.

>Commercial profitable nuclear fusion is a maybe by the end of the century.

https://www.youtube.com/watch?v=GD8EdXuU9Ms

10-20 years max. Deep Mind will work on it.

Will you believe Deep Mind when it tells you it cannot work?

> if we're serious about global warming and the overall health of the planet

There’s a saying that when someone shows you who they are, believe them.

It’s pretty clear that “we” as humanity are not serious about global warming and the overall health of the planet.

Some of us are making gobs of money and think we’ll just be able to buy our kids the same great life we’ve had. Some of us are complacent and don’t worry too much about the future. Some of us are so desperate to survive today that we can’t think about tomorrow. Some of us realize it’s a lost cause.

“Fixing” global warming just isn’t going to happen. We spent the money we didn’t have over the past few decades and the bill is coming due soon. At this point it’s all about how we cope with a world that’s going to be unimaginable to many of the people alive today.

> “Fixing” global warming just isn’t going to happen.

There will be likely last-ditch efforts from desperate governments and technocratic industrialists to do geoengineering, with all of the expense and potential blowback that entails.

Some attempt to darken the skies probably won’t happen in my lifetime but I sure wouldn’t want to be alive in 200 years.

Maybe the O’Neill colonies will be ready by then.

There's a weird sociological phenomenon where people declare that "renewables won't get us there" without any real justification.

A recently announced deal in California would build out solar for $20/MWh compared to your $200/MWh nuclear worst case. Renewables can and will get us 90% of the way there. I recognize that a renewables based grid will require massive investments in grid infrastructure, which are long overdue anyway, as well as eventually storage/batteries, which is still on an exponential cost reduction curve. Bbut given the massive cost difference of generation, that would still be a dramatic net benefit.

Particularly when nuclear plants take a decade to build compared to a year for a solar plant.

I get that nuclear is cool, particularly fusion, but I really don't understand this "renewables won't get us there" argument beyond that.

Seems like in 2022 renewables are getting us there: https://ember-climate.org/insights/research/global-electrici...

> +389 Change in global electricity demand (TWh)

> +416 Change in renewable generation (TWh)

> +5 Change in fossil generation (TWh)

I'm confused by this, it doesn't add up: change in renewables + fossil generation = +421TWh, so why does it say +389TWh for change in global electricity demand? Is 32TWh just going to waste?

Maybe a third category (perhaps nuclear) went down? Just speculating, it isn't very clear.

Are they ? Seems like we're using just as much fossil fuel as previously, which is still waaaaaay too much for any kind of sustainability

As always the rebound effect is kicking our ass, instead of producing the same and polluting less we pollute the same and produce more

Whilst I understand that in reality the costs will always win out, I think only addressing the cost aspect is a strange way of tackling the issue given that cheap energy has gotten us where we are.

Not to mention that you're comparing costs unfairly, given the costs of nuclear include the costs of processing and storage of waste output, and nuclear is the only energy source in which we control all outputs and have dedicated and well engineering processes for dealing with those outputs.

I think that people are being completely unrealistic regarding the cleanliness of solar and wind, currently we bury the blades and we just turf the panels, both of which are hardware that needs to be upgraded. The heavy metals in panels do not break down at all. Which is funny given everyones focus on the radioactivity of nuclear waste, which even though takes a long time to completely stop being toxic, does actually stop being toxic.

I think there's a happy middle ground, and we need a good mix of sources, but people are comparing on features that they want to compare on, and ignoring others.

Burying blades is worse than burying nuclear waste?

I think I understand the point you're trying to make, but funnily enough, based on the current methods, yes.

That's not to say that the blades are more dangerous than the nuclear waste, just that the nuclear waste has many years of waste management engineering behind it, due to its danger. So there are defined processes of management that are well tested, well designed and well implemented.

Processes for blades currently are just bury them in landfill, which causes a bunch of unmitigated issues.

https://www.bloomberg.com/news/features/2020-02-05/wind-turb...

The idea that we "just bury" nuclear waste in the same way a dog buries a bone, is kinda funny, but very far from reality.

This also doesn't even touch on nuclear waste recycling, which is enormously beneficial.

So you're saying there is years engineering experience behind nuclear waste management but burying wind turbine blades is somehow completely uncharted territory? Tell me how many landfills/regular waste processing plants (or are wind turbines fundamentally different?) exist compared to existing long term nuclear wast storage facilities? Do you think no engineers are involved in designing landfills? If you think the waste from wind turbines are a problem, what about the carbon fibres from all the other things (cars, planes, bikes...) that produce orders of magnitude more waste.

Same goes for solar cells, the recycling process is similar (but easier) than most regular electronics and if you think nuclear power plants don't require heavy metals in their construction, boy have I some news for you about what is in your laptop/desktop.

All I am reading is just how influential the nuclear lobby groups up if they can make these stupid comparisons and get away with it.

You might want to update your research on the state of play of turbine blade disposal. There are several companies with active recycling programs in place and scaling as we speak that do everything from recycling the blades into perfectly reusable fiberglass and fuel materials to converting them into building materials.

As far as disposal of nuclear waste goes, yeah there's a ton of engineering involved because the stuff is just that big a pain in the ass to deal with for any length of time. Given half-lives typically range between 30 years and 5 times the length of recorded human history and that the rule of thumb for "safe" levels of emission are 7 half-lives we're talking about borderline geologic time frames before certain types of waste meet anyone's definition of safe. We could also spend a moment here reviewing all of the incidents in the last 40 years where source material has managed to jump a fence and ended up crapping up an entire village or neighborhood. All of that is to say that anyone peddling the notion that storage of radioactive waste is a solved problem either has an agenda and no ethics or is grotesquely uninformed.

I'll give you this: nuclear proponents are really dedicated to twisting the facts to fit the narrative. "Actually, yes, large fan blades in landfills are worse than nuclear waste." Good stuff.

It looks less silly when you acknowledge the problems while explaining how they are outweighed by the benefits.

Here’s an enlightening calculation to do: total volume of fuel used by nuclear power plants over 100 years providing enough energy for the world vs total volume of turbine blades doing the same. Feel free to be generous with your lifetime estimates for turbines, the results will still be shocking. You can also repeat the calculation for any other fuel source or power generation method and be equally impressed.

The notion that turbine blades are not and cannot be recycled is a bit behind the times. Carbon Rivers is scaling up their turbine blade recycling capacity as we speak.

https://www.energy.gov/eere/wind/articles/carbon-rivers-make...

EOL turbine blades have also been used in several architectural projects as everything from a concrete reinforcing agent to actual structural components.

Solar panels are currently still problematic, however there is huge industry spend on recycling R&D. Are you prepared to bet the farm that recycling tech won't run down the problem in less time than it would take to permit and construct a nuclear power plant given the 5 years it takes to permit one and 7-10 years it takes to construct?

If we're gonna talk of stuff in the pipeline, don't forget that nuclear Gen 3 reactors can actually reuse current waste and reduce it by up to 90%.

Currently those reactors only exist as experimental reactors, so it's fair discounting them. Same as it's fair to consider the waste generated by wind since the vast majority of blades end up in landfills. Even though on theory they needn't.

Difference one being that the wind turbines can start producing electricity and remove carbon emissions within months, while building a new reactor happens within years.

Difference two being that after those gen3 reactors are done you still have 10% of waste which can be used to wipe out cities and ecosystems, while after you are done recycling turbine blades you have slag and (if properly neutralised) chemically inert goo

Except those recycling technologies exist at scale and are prohibitively expensive.

This is where PWRs are after 60 years of maturing the technology and there are many low hanging fruit to be picked because there have not been large quantities of silicon panels for more than a few years.

Those Gen 3 reactors are still steam engines, and it's questionable whether steam engines can compete even if the heat source is free.

The silver and copper in silicon panels is extremely valuable for recycling and is economically positive and CdTe panels are obsolete. CdTe panels are recyclable, and you would be most welcome to help pass a mandate that they get recycled -- the added cost would be a rounding error on total system cost. The silicon is also recyclable at energy-positive rates (although gathering it is not economically positive at the moment).

Windmill blades are inert, downcyclable and smaller in mass per joule than low grade nuclear waste.

I work in the solar industry, and very few large projects are turfing solar panels anymore. There are at least three companies that will usually bid against each other to purchase used/broken solar panels for recycling/reclaiming materials.

One of the early issues with recycling companies scaling is that solar modules don't break very often, so there hasn't been enough volume to get the industry off the ground. Solar modules are generally good for 10-40 years, so we're just starting to get the first generation of decommissioned plants (which by the way, are generally being repowered with more efficient modules).

Same with wind turbines. In any case, outside of the valuable heavy metals, landfills really aren't that huge of a problem, despite consumer focus. Decommissioned landfills are already a hot commodity among solar developers in the Northeast for instance because they're great, relatively flat, centrally located land that you can build a solar farm on. So as long as we're succeeding at reclaiming heavy metals, the waste generation component is pretty trivial. They're really just part of the cycle.

Finally, the decommissioning cost of solar plants is usually bonded in with a utility PPA to be borne by the project company, just like with nuclear, so it is indeed a fair comparison.

I agree regarding our regulatory environment for nuclear being counterproductive (it's counterproductive for wind and solar too, though to a lesser extent). However, even in positive regulatory environments such as France, Nuclear costs 3-5 times as much to build on a $/MWh basis and takes much longer to site, permit and construct. There may be a small role for base-loading nuclear in certain areas that have poor renewable resources, but it otherwise rarely makes sense, regulatory issues aside.

Out of curiosity... for utility-scale solar, do they tend to dismount the old panels, or just leave them in place for whatever small fraction of their original generating capability they still provide?

I imagine that they'd eventually run out of land to put them on, but from what I've seen, utility-scale solar often sits in places with a fair bit of room for expansion.

Modules degrade in production really slowly (<1% per year) and are often used for 40 years. They're generally replaced quicly if they break due to manufacturing defects or impact damage (hail, tree branches etc.). A lot of the recycling of solar panels is for panels that are a decade or two old but in perfectly good condition. What's happening is that new modules have increased 30-40% in efficiency over the same time frame that the old modules have decreased by 10-15%. So its cost effective to upgrade them in certain cases - generally where the utility will allow it.

The other factor here is that many agreements between a solar power and a utility that buys the power only have 20 year terms. Generally, there's a strong incentive to renegotiate at the end of the term, but frankly, that renegotiation is kind of a mess in practice. It depends on the policies of the state, the utility's interests, the ISO market, etc. as to how that ends up working. Every solar farm is working in at least five overlapping regulatory environments - local, state, utility/retailer domain, the ISO or regional grid, and the federal regulatory environment. Decentralization is nice in theory, but definitely makes it difficult to scale the widespread change that's required right now.

Cheers for the great comment mate! I replied to you initially and I am still learning about this very vast topic, I try not to take a partisan approach to this stuff as it is obviously important, always trying to update my understanding and I do change my position as I learn new stuff.

It's interesting to hear that the recycling processes have changed, how recent of a change is this? I took my viewpoint from what seemed to be a overwhelming amount of (what I consider to be non-biased) resources, around the panels "being" recyclable, but not actually being recycled. And I don't think it's unreasonable to be wary of toxic waste given the entire purpose of this thing is to clean up our energy system etc.

I also wasn't aware of the decommissioning being bonded, cheers for that.

Do you think there's a difference between (what I assume for you is) the US and other countries progression along the lifecycle of solar? I feel like in Australia where I am, a lot of the articles I'm seeing are bringing up that what you've mentioned as solved problems, don't seem to be here. I will admit though that we are fairly useless being an economy that derives so much from coal exports.

Yeah so the pricing thing I do understand, but I also just think it's important to continue nuclear as an option anyway for future improvements and general management of brain drain.

Cheers for being chill, I find topics so divisive these days, I never mean to come across and ignorant of other opinions and I try to engage and not just be a "this is my tribe and I'll die on this hill", this problem is too important for it to be a "I'd rather be right" type deal.

Thanks for checking me on my U.S.-centrism and your comment as well! For the record, I think Australia's market is a bit younger even though it's already a bit larger as a percentage of power consumed than the U.S.'s thanks to some amazing solar resources in the desert. I'm fairly certain that all of this gets much easier for everyone at scale - it's just a matter of waiting it out until there are enough modules ready to recycle to generate regular revenue for recyclers, so it's likely just a waiting game.

Uranium-238 decays into lead. No longer radioactive, but still toxic.

You are right. I believe the disconnect with many of those who argue like your parent is that they expect no societal changes should be forthcoming. So nuclear (both kinds) is the only way to continue with this lifestyle. As wastefully as we may wish, since massive over-provisioning is a possibility with these technologies.

I disagree with the premise and therefore with their conclusion. Renewables (plus storage, plus demand management, plus HVDC transmission) will get us there. But there isn't here

When I read here about nuclear as a solution I never read about how much fuel there is left, where it comes from, how much CO2 digging up the fuel and processing it is created as well as the waste management.

The waste is not a solved problem. In Germany we have huge problems with it hence why nuclear is on the way out.

Nuclear in France had problems with running during the summer due to the water in rivers being too hot and the system not maintaining the correct temperature difference.

Those numbers are easily found but you also have to ask the same questions about waste produced by manufacturing renewables.

Good questions. Just the first question is a rabbit hole on its own. How much nuclear fuel (lets focus on uranium) is left on Earth ? https://en.wikipedia.org/wiki/Peak_uranium Looks like there is uranium everywhere, including under your feet. There is more uranium than gold for instance. The question is about cost to extract. The more you spend the more you find. And the more you look and the more you find. "As of 2017, identified uranium reserves recoverable at US$130/kg were 6.14 million tons (compared to 5.72 million tons in 2015)".

Then on the other hand, it depends on how much uranium we use. "LWRs only consume about half of one percent of their uranium fuel while fast breeder reactors will consume closer to 99%. Currently, more than 80% of the World's reactors are Light Water Reactors (LWRs)."

So moving to fast breeder reactors would essentially live us with enough uranium for hundreds of years.

The justification is that renewable* power can not be easily adjusted to match demand and storing electricity on a large scale is tricky and expensive

*really just solar and wind, which seems to be mostly what people mean when they say renewables

A weird thing to bring up when nuclear has the same problem. Making reactors that can respond to load is.... not cheap or trivial. And basic baseload type start out an excessive level of expense and complexity.

Running a reactor over the grid demand load is wasteful of fuel, but can be done whenever. You just factor that into your cost equation.

A renewable does the same thing, but when there isn't sunshine or wind you cannot just bring more in.

It's trivial to shut off an inverter or to feather a wind turbine's blades and stop generating.

Throttling a nuclear reactor can not happen as quickly, and the have much slower ramp rates as well.

Pumped hydro storage was developed because of this reason. We would likely use batteries today, instead of more pumped hydro.

Missing my entire point: you can't cycle up renewables whenever you want, and that's the problem.

If you want to cycle renewables up, but can't because of limited capacity, the one simply hasn't installed enough renewables or storage.

Same answer for nuclear, if you can't turn it up enough, then you simply haven't installed enough.

Storage can help mitigate the ramping concerns about having lots of nuclear on the grid. For France to be able to have 70% of generation as nuclear, they depend on using the continents grid for balancing, in addition to having some very high priced fast damping nuclear plants. But charging storage with solar, and using that stored electricity, is cheaper than using nuclear in the first place.

And at current prices of roughly $200/MWh for nuclear, and $20/MWh for solar, you can throw away an awful lot of solar capacity before nuclear makes any sense financially. And at $160/MWh for storage, which is a levelized cost which includes charging at ~$50/MWh, there's even room to not use all the battery capacity everyday and still have a firm energy source cheaper than nuclear.

This isnt true:

https://reneweconomy.com.au/a-near-100-per-cent-renewables-g...

Storage isnt particularly cheap, but while solar and wind are 5x cheaper than nuclear power it is waaaay cheaper to combine solar+wind+more storage for a fully dispatchable grid than it is nuclear+less storage.

10 years ago people said nuclear power plants take 10 years

Battery technology is NOT on any kind of exponential curve.

We’ve been waiting decades for the promise of renewable energy. Time is running out quickly.

100 million barrels of oil a day and 40% of electric power generated from coal.

I get that no one likes to admit they were wrong, but it’s 2022 and not 1985. All that squandered time means we’re unlikely to avoid serious climate issues

UPDATE

Just to be crystal clear: Battery technology is NOT on any kind of exponential curve.

People who are telling us to wait because they think they’re improving exponentially are sending us past the point of no return

> 10 years ago people said nuclear power plants take 10 years

More like they said five, then ten after five years ahf passed.

>Battery technology isn’t on any kind of exponential curve.

Thats simply false, and a weird thing to fabricate. The very idea discredits the rest of a person's assessment of tech.

https://news.mit.edu/2021/lithium-ion-battery-costs-0323

> I get that no one likes to admit they were wrong,

This is some extremely strong projection. J'accuse

Where do you see an exponential curve?

The article doesn’t discuss any exponential decrease for a reason. And most of the “dramatic drop” looks like it happened in the first 10 years

Time is running out.

Ok, here's one with a log scale so you can clearly see the exponential trend line

https://spectrum.ieee.org/chart-behind-the-three-decade-coll...

“Between 1991 and 2018, the average price of the batteries that power mobile phones, fuel electric cars, and underpin green energy storage fell more than thirtyfold”

THIRTY FOLD ISNT EXPONENTIAL.

Please reevaluate the plan. It likely contains a lot of optimism and a few required miracles

> THIRTY FOLD ISNT EXPONENTIAL.

A * exp(b * t) = A / 30 => b = - log( 30 ) / t

As far as I can see a thirty fold decrease does fit into any exponential curve if you have the right rate constants or times, so I don't really get what you mean with that.

The data is right there, it's on an exponential cost decrease. Very weird to be pointed directly at the data and deny that it says exactly what it says.

You say that "nobody likes to be proven wrong" but I in fact do like to be proven wrong. The "nobody" appears to only apply to yourself.

What do you mean? 10 years ago all the nuclear proponents were arguing against renewables because they are too expensive supposedly. Now they are cheaper they make up new bogus arguments. Nuclear has had 70 years of massive subsidies (even excluding military spending) is still more expensive with lots of unsolved problems, but you say its the solution because renewables&storage are not reducing prices fast enough? Have a look at the price curves for solar, wind and batteries I can tell you only 3 of them are exponential price reduction curves and nuclear is not one of them.

So we waited for the renewables and lost another decade. Solar and wind are up to perhaps 10% global usage?

Maybe we can get it to 25% by 2030?

Hopefully we can stop building coal plants. Incredible emissions. 40% of global electricity…

And Germany is restarting

https://www.nytimes.com/2022/06/19/world/europe/germany-russ...

If your target is 2030 that's not enough time to permit and construct a single conventional nuclear power plant in North America. The permitting process alone typically runs 5 years or more before ground is even broken on construction.

Yeah, yeah, I heard all this 10 years ago. I imagine you’ll be saying the same thing in 2030 when coal usage will be about 35% of global electricity.

I'm not sure I follow you here. It takes 12+ years to permit and construct a nuclear power plant in North America. This isn't a matter of opinion but of observed reality. They take on average 7 years to build with a 5+ year long permitting process before ground is broken. So unless you're proposing the government imminent domain a bunch of reactors into existence I don't understand what we're even talking about?

That the best time to start building a nuclear plant was 12 years ago. The second best is _now_.

No, we can build double the capacity if we build wind and solar now and the wind and solar will reduce or CO2 emissions while the nuclear plant is still in the planning/building phase, why should we build nuclear?

Double of zero is still zero.

Do you have an actual argument? Offshore wind has a capacity factor of 60% that is close to nuclear power plants. If you locally distribute your generation, the chances of power falling to zero goes to zero.

And completely shuts down about once a month.

I'm sure we can deal with a 30% electricity deficit that happens randomly with a few days notice. We can shut down unimportant things like residential power. No one really needs lightbulbs every day of the month after all.

Do you know what a capacity factor is? Do you understand how overprovisioning works and why we would also need it with nuclear power (at a much higher price)? Do you have any numbers to back up your once a month claim and 30% deficit or are you just making stuff up?

Yes.

Maybe permitting shouldn't take 5 years?

Maybe not. Between NIMBY groups and the political polarization around climate change I think we can all pretty vividly imagine what Twitter would look like 60 seconds after draft legislation to this effect was proposed.

Why did you wait? A poor country like Brazil is already 80% renewable for electricity. You cannot buy pure gasoline at the pump. It's mixed with a minimum of renewable ethanol, and that minimum has been going up every year for over a decade. Almost all cars run on pure ethanol and some consumers choose to never use petrol based fuel for their car. Diesel is not pure either. It's mixed with biodiesel by law and that percentage goes up every year.

If a poor country can achieve this, there is nothing stopping much richer countries.

You didn't lose a decade due to renewable capabilities. You lost a decade due electing the wrong politicians, influenced by big oil.

Carter installed solar panels on the White House. Reagan removed them two years later. It's nonsense like that that resulted in your lost decades. While other countries were already racing ahead.

> renewable ethanol

Is it really renewable? (I don't know, but I assume biofuels are only viable with massive fertilizer subsidies. Also, I hope "renewable" doesn't mean "let's cut down the Amazon rainforest and wait 200 years for it to grow back".)

You get a new crop 2x a year as opposed to waiting 180 million years for new fossil fuels, so yeah, it's really renewable. As far as net carbon, I'd like to see the math but since plants take carbon out of the air it's far closer to carbon neutral than burning fossil fuels.

Cutting down the Amazon to power cars would indeed be foolish but the same folks protecting the Amazon are the same folks pushing renewables. Likewise, the current president turned a blind eye to deforestation while pushing for more fossil fuels. For the time being if you want to protect the Amazon it's the renewables folks you need to get behind.

Does battery technology need to be on an exponential curve? We already have electric car batteries that can power your home for a good long time. Note that a battery for a home is cheaper as there is no weight restriction, unlike with a car. You can use old refurbished batteries that are no longer suitable for cars.

On the grid scale, a pumped hydro facility can provide energy storage for thousands. Energy storage is technologically a solved problem, it’s just not equally distributed yet.

I’d like to see a cost estimate in both dollars and land area for pumped hydro.

Solar reliability is a big unsolved problem. Even at nation-state scale, we can't store power at enough scale without having to massively overbuild and even then.

The right way to fix this of course would be to take the same technology that lays undersea fiber optics, and take REBCO superconducting tapes and lay completely efficient under-sea power cables to locations with 8 hour separations around the world, then build solar their. It becomes a very different equation if you start having reliable sunlight.

We could do this today - none of it requires new technology. What it would require is a degree of international cooperation and trust which would be more or less unprecedented.

I do kind of wish some "change the world" billionaires would get interested in this, because it's an expensive project but it can both make money and is not the sort of the thing that requires more then commercial cooperation agreements to get started. And a single, global-scale electricity grid would definitely revolutionize things.

It’s one form of risk to potentially allow your adversary to cut your undersea communication channel which has an over the air transmission backup, quite another to allow an adversary to cut your energy channel used by all homes hospitals and businesses, and with even less of a backup.

To get a billionaire interested you can’t position this tech as a global solution; it’s a nonstarter. However you could get a billionaire interested if you identify an economic arbitrage opportunity it enables that isn’t easily eroded.

For renewables to be renewable you have to make the solar panels and turbines and storage systems from the energy generated by solar panels and turbines - from raw materials to raw materials.

When you do that you find that although you may be able to build the current version of renewables cheaply, that is because we are leveraging very cheap fossil fuel energy from China, and a world full of fossil vehicles, not sustainable vehicles.

Renewables wear out - far faster than initially thought - particularly turbines. When they come to need replacing the costs will be very much higher - as the material and power requirements will be competing at that point with a world that can't use fossil power or fossil locomotion.

Nuclear, on the other hand, can go the other way. Nuclear power in a shipping container (ie the same system we use on submarines) should mean we can bring economies of scale to fission, using little more than steel pipes and a bit of wiring, with the waste transportable in the same way as submarines. After all we've been able to control nuclear plants since the 1950s using relatively simple technology.

> For renewables to be renewable you have to make the solar panels and turbines and storage systems from the energy generated by solar panels and turbines

This is only true if you're going for some pedantic definition of renewable energy where it only counts if you're at 100%. Which, this being HN, is the kind of thing I expect but...

The reality is different: we need to reduce the impact of climate change by any means necessary since are already in a state of climate emergency. If we calculate that using fossil fuels to build solar/wind turbines/wave energy/etc. and then using those to power homes will be a net negative in global emissions, then we should do it. We can build the next generation using renewable energy.

Worrying about whether this fits some definition of renewable energy is just a distraction. Renewable energy is not the end goal, tackling climate change and reducing pollution is.

I don't think you answered the argument there, merely suggesting it's fine to kick the can down the road because "emergency now!"

First, we need to look at where renewables are being used and if they're actually in the areas of greatest pollution, i.e creating a net reduction rather than just meeting a government number.

The relevant metric is joules of forcing avoided and joules of forcing avoided per dollar. Nuclear is very rarely a good choice by this metric even compared to changing coal for gas.

I believe that the argument is that you should calculate "pollution per kWh" along the entire lifecycle, not just restricted to the operating time.

This will surely still put most renewables in front of fossil fuels and (depending how you count it) most nuclear.

But it is a largely ignored metric by the general public

> There's a weird sociological phenomenon where people declare that "renewables won't get us there" without any real justification.

Sun doesn't shine at night.

The end.

Rivers flow, when it is not raining.

The beginning.

>From the Danube to the Loire, Europe's prime rivers — lifelines for the continent's economy — are running low after a brutal five-month drought. After years of dry weather, scientists are warning that low-water conditions could become the norm in Europe as the climate changes.

https://e360.yale.edu/features/europe-rivers-drought

Not any more.

Similar story for the Colorado river in the US.

Just add some other renewables, storage, load shifting and interconnects, and the story continues.

At ten times the cost of a nuclear plant of the same capacity.

There is always some place in the planet when the sun is shining, and it is happening since the entire history of the planet.

Imagine a world when we could move stuff and communicate with the other coin of the planet from coast to coast. We could call it pipelines, internet, telephone cables or something like this. Can't wait for this to be invented

Sure, at that point nuclear power is cheaper building and maintaining that grid.

Cheaper only until you have a war, or a tool taking shortcuts in managing the place

The nuclear central of Vaporhizeyou in Ukraine is a liability? In some aspects, for sure it is a weak point in the safety of Ukraine. It depends on the point of view and in what direction the winds blow.

There are also just as many people stating "renewables will get us there" without any real justification...

California is an excellent place to build out solar. They got the Mojave Desert, the Colorado Desert, and the Great Basin Desert, the later being the largest one in North America. The only time they need storage support is for the predictable hours of the night, and rare weather conditions. The first is solved by a few hours of battery capacity, and the later is solved by fossil fuels or imports. They don't even need that massive investments into grid infrastructure to span the distance between deserts and population centers.

California is the great example for solar power without needing a lot of storage/imports, in a similar way that Iceland is a great example for geothermal.

Sabine Hossenfelder had a pretty good video about the issues not yet solved with renewables. In particular we don't have viable method for storage

https://www.youtube.com/watch?v=Q8xsg9iK5yo

The short version, when the sun doesn't shine and the wind doesn't blow you need storage. How much, in many places you'd need several weeks of storage.

One way to do storage is to pump water into a reservoir. That is currently 80% of our storage. We'd need 500x what we currently have in that kind of storage to cover our needs. For batteries, we'd need 250,000x the amount of all batteries the currently exist in the entire world. She goes over other methods of storage.

She also goes over how much energy we get from things. Examples:

1kg of oil generates 13 kWh (13 kilowatts for 1 hour or 1 kilowatt for 13 hours)

1kg of coal 8 kWh

1kg of lithium battery 0.2 kWh

1kg of water 2.7 Wh (not kilowatts, watts so 1000x less)

1kg of uranium 24 GWh (24 gigawatts, so 1 million more than oil kilo->mega->giga)

She also goes over how much pollution the storage itself makes.

The amount of storage required is perfectly doable:

https://reneweconomy.com.au/a-near-100-per-cent-renewables-g...

It's also quite a bit cheaper doing this than building out enough nuclear power + storage to service our needs.

overshoot production, my go-to way in Factorio until mass-production accumulator is available

> The amount of storage required is perfectly doable:

Snowy 2.0 can provide about 5% of the power NSW needs. That means we only need to build another 20 of those.

And that's only for power, we're not even talking about energy here. And we're already out of mountains. So no: it isn't doable even until we can build mountains on demand.

>we only need to build another 20 of those

The study says one more.

The study is written by morons.

If they can't divide a number by another number they should stick to eating glue.

You're not comparing like for like.

First in a PWR (the only nuclear technology viable even with subsidy) 1kg gets you 150MWh not 24GWh. This is even more misleading than pretending a solar panel will produce 1.3kW/m^2 every hour of the year or pretending a lithium battery is 10kWh/kg based on the voltage and the density of pure lithium.

Second the uranium is only a tiny portion of the unrecyclable waste and a miniscule fraction of the reactor. The net mass power density is not much better than wind, or par with wind and worse than glassless solar. Naval reactors have higher power density but have much stricter operating conditions and costs that cannot even be borne with tax money covering the bill.

Solar + battery has powered a multi day flight. Nuclear has not.

Additionally comparing cost for cost, nuclear requires just as much storage as renewables because storage is vastly cheaper than paying $12000/kW for capacity you only use for 100 hours a year.

In a context where you're considering the labour and resources required to provide the energy with fission, storage has been solved for a decade.

If we come back to the real world and consider the only metric that matters of joules of radiative forcing removed per dollar then there are only a tiny handful of places you'd consider putting a new nuclear reactor, and then only once you'd paid to maximise the renewables in the region.

You need less ressource (metal) per GWh with a nuclear power plant than with solar or wind. The Uranium waste for a French person is about 10gr/year (France is 70% nuclear when it comes to electricity).

That only accounts for a small fraction of primary energy (about 300W Net). It also does not include all of the high level waste or its containment vessels and shielding (which are many times heavier).

The mast on a wind turbine is inert and recyclable and the nacelle is fully recyclable. A 15MW or 10MW net wind turbine blade assembly is about 100t or roughly 4t/yr. At 300W per person that is 120g of fiberglass. It is fully downcyclable at positive roi.

A solar panel frame is inert and recyclable, as is the glass. The part generating the energy which wears out is about 5kg for 400W (upper bound based on glassless hail resistant panels available at retail) or 1kg/20W net of mostly-sand for a 20 year life. This is 750g/person or a few times more than the uranium + storage facilities, but hardly prohibitive and fully recyclable at near break even cost (you can even turn them back into new solar panels without re-purifying at reduced efficiency). The glass is substantially heavier, but if you're pretending we as a civilisation can't have 30kg of glass per person, then I really don't know how to talk to you -- it's such a non issue that panels are rarely optimized for mass even though doing so adds very little cost.

The low level waste and inert recyclable structure of a nuclear reactor is commensurable with the 1200t/10MW of a wind turbine and also the ten or so kg per 100W net of solar. The concrete holding up the wind turbine is substantially heavier. Solar requires little to none. Solar can coexist with other uses for the structure or land.

Plus fission has its own problems and is very expensive and the storage problem is not solved.

Doesn't mean you should turn of any power plant, but it is just not a very good or efficient way to generate energy right now. Economic considerations will always restrict security. It was the case in Japan and will be the case everywhere else as well.

Fission is only efficient if you manage to reduce the question of ecological impact to CO2. But the overall calculation is far more in favor of renewable forms of energy.

Nuclear waste storage is solved. And for the last generation (4th) of nuclear power plants, the waste gets back to natural level of radioactivity in only 1,000 years. We have in France bridges that are older than that.

Running a nuclear power plant is very cheap. Building it is expensive and requires lots of capital upfront. The cost of nuclear is mostly interest. That is why it is a bit more expensive in UK (private capital) vs France (state capital).

How "the overall calculation is far more in favor of renewable forms of energy." ? In order to build enough solar or wind, plus batteries to replace all the nuclear production, we will have to extract a lot of resources (rare earth, lithium, etc.) pour a lot of concrete (for wind) which creates a lot of CO2, make lots of iron (energy hungry and producing lots of CO2). And all the waste involved, and they also have a lifespan, and needs to be replaced over time.

Not saying that we should not use solar/wind. But I am not convinced that it is the silver bullet and we can replace all the current and growing energy production with solely solar+ wind. It seems to me more reasonable to have a base line with nuclear, esp. if CO2 reduction and preparing for oil/gaz/coal peak are the goal.

Yes! And without data to back that up.

Auke Hoekstra would disagree with the claim EE alone is not sufficient.

https://twitter.com/AukeHoekstra/status/1557466581185224704

Mmm I think renewables could cover it without the need for fusion. I think there is one potentially big issue with renewables though. The supply chain for panels, wind turbines and batteries involves China quite heavily.* This year has been a hard lesson in the essentiality of energy security. Depending on what plays out geopolitically, renewables could suffer from deglobalisation and increasing hostility between superpowers. The low cost per MW of renewables obviously makes some supply chain assumptions. * This issue also pertains to fossil fuels, particularly gas infrastructure.

I also think that it is worth noting that renewables are a peaceful and ubiquitous energy source. Successful fusion would carry significant military advantages, which may cause a lot of disruption depending on who gets it first. This is always the way when someone develops a denser energy source.

Takes too long. Remember it takes decades to build 1.7 miles of track.

Renewables' innovation is in being small repeatable project.

You will never overshoot production, if crypto mining can waste any amount of energy.

I love to follow this field because the engineers working on tokamaks/stellarators/other fusion devices are dealing with some truly extreme technical challenges. However, creating devices that economically overcome those challenges at scale seems unlikely when solar panels and batteries are aggressively decreasing in cost. How will these compete if scientists figure out the longevity problem for perovskite solar? Just my opinion as a layman. I still think the research is worthwhile because of possible future applications (space?)

There's only so much surface area on the earth that we can cover with solar panels and global energy consumption is exponential. Abundant energy will enable more possibilities such as removing CO2 from the atmosphere, desalinating water and pumping it into arid regions, and opening up space tourism for the majority of the worlds' population.

False.

There is exactly zero need to devote any land surface at all exclusively to the solar panels that will provide for all our needs. Solar coexists nicely with numerous other uses. Similarly, for wind turbines.

Storage may consume some area, but nowhere near what existing fossil fuel extraction activities do.

There will be no fusion.

> There will be no fusion.

Scream it into the ether with veins popping out of your head all you want, it doesn't make you correct.

Additionally, there's literally no reason to not pursue both avenues.

Nobody is screaming.

Even presuming usable structural materials can be discovered (not worked on in 3 decades) and tritium at PPB concentration can be extracted from thousands of tons of blanket material every day (never worked on at all), a working plant would cost more than an order of magnitude more on every axis than fission.

But fission is already not competitive. Fission falls farther behind better methods each day.

So, no one will build a fusion power plant, and there will be no fusion power. "Pursuing avenues" with no possibility of desirable results is wasted effort and wasted money. We have valid reasons to avoid waste.

If no one is building fusion power plant, what money or effort is being wasted? Also, do you think all of these nuclear physicists are able to pivot to working on renewable energy, as if they are Silicon Valley tech startups? From what point of view of action are you even operating from?

Doing science is fine.

It's the thousands of scam artists that will divert resources from actual solutions as soon as their lies are plausible to rubes that are not.

If we're busy paying for 100s of victoria county stations that will never open, the coal plants will remain on.

But that has literally never happened nor is likely to happen, given the political marginalization of nuclear power.

The previous poster is ranting against a tiny threat, if even that, to wind and solar while the fossil fuel lobby reigns supreme. Just a completely disproportionate response.

There is no such "threat".

Investors are being defrauded. Money that could be going for important, useful research is being diverted to pockets of fraudsters promising sky castles.

There's no telling that that money would be going to renewable research anyway. So why all of this concern? There is no imminent decision between the two. Those investors would not be spending the money on endeavors you care about. If it is a fraud, then let that money be wasted to prove the concept a fraud once and all. You should welcome that, as that would further your position in a definitive way before the public.

>" If it is a fraud, then let that money be wasted to prove the concept a fraud once and all. You should welcome that, as that would further your position in a definitive way before the public."

No Fraud does damage , it's not money wasted to disprove a fusion is viable , its resources and time just wasted. Just because "oh that money will never be used for other stuff anyways" doesn't mean one shouldnt voice for better utilisation of it.

Theranos was Fraud , doesn't mean we've proved minitiarized blood tests are impossible

That is an excellent point conveyed excellently and I agree with it.

> The previous poster is ranting against a tiny threat, if even that, to wind and solar while the fossil fuel lobby reigns supreme.

The current tirade of nuclear shilling serves the fossil fuel industry. As does directing funding (often including public money) to all the 'fusion' startups like helion with massive, obvious, unpatchable deal breakers in their plans. A billion going to general fusion could fund tens or hundreds of hysatas or natrons, a non-zero proportion of whom are making real progress towards actual solutions.

Vogtle, Hinkley, VC Summer... the list goes on and on. The people wind up paying for decades even if no power is ever produced. There has never been a commercially viable fission reactor even with the free unlimited insurance.

The fission industry has been burning enough public money every few years for decades to have kick started the renewable economy. A large portion of the massive cost reductions we saw in the last ten years have been technologically available for a very long time -- the only thing needed was investment in the engineering. There are still problems and technologies best served by primary research that will help and have a far better chance of paying off than more money down the fission toilet or towards snake oil fusion scams.

The same tired lines get rolled out every time and they're always wrong. Every discussion about the actual solution gets derailed by some combination of fission shilling, fud about variability or 'don't invest in renewables, fusion will save us'.

Is there any actual book or article or any sort of source at all that shows that nuclear is an existential funding threat to renewables, rather something that has been politically moribund in the U.S. ever since Chernobyl, if not Three Mile Island?

Given how disadvantageous a position nuclear has been at for all of this time, it's probably trivial for pro-nuclear adherents to turn around and call the anti-nuke lobby shills for the fossil fuel industry. And so round and round the circular firing squad goes.

Nobody said "nuclear is an existential funding threat to renewables". You made that up from whole cloth.

Stop doing that.

You are the one claiming that any money into nuclear funding detracts from funding of renewables. If that in fact is not an existential threat, then you should probably tone down your verbose vehemence to the former. If it is not an existential threat, then you are thundering against a non-issue.

You stop doing that.

I am not, in fact "thundering". You made that up. Stop it. I said nothing about "existential threats" or "threats" of any kind. You made that up. Stop it.

Every last dollar going into fraudulent fusion startups, and via federal grants from taxes into constructing ITER, is in fact diverted from potentially productive research. Fraud is a pure negative.

Okay, so you’re saying something can be a pure negative, while not being an existential threat. Thank you for explaining your position.

What is Helion's showstopper? I mean, they're a longshot, but as far as I know there's nothing that guarantees their effort doesn't work.

Two things.

1) World helium-3 reserves mean they can only be an irrelevant amount of total energy. Otherwise it's just D-D or D-p fusion with extra steps (and all the neutron problems involved).

2) The magnetic energy recovery can at best reach parity with the thermal, which makes it yet another solar freakin' roadways if not a theranos. They play sleight of hand with this in all their marketing materials which indicates they know it's a show stopper but do not want anyone paying attention to it.

The slick marketing, the sexy story, the massive hole in their story, and the startup posturing put them with every other scam startup that promises the world and then folds after an IPO with VCs disappearing with a the later investors' money.

In DD followed by D3He most of the energy is coming from D3He, especially if you let the tritium decay (admittedly that takes a while.)

The magnetic energy recovery scheme would allow the energy of compression to be recovered at high efficiency. If this worked, they could have a practical, energy producing system even with Q < 1. I believe they are aiming for Q = 0.2.

The idea that it "can at best reach parity with thermal" seems without any justification. Perhaps we could debug the source of your misunderstanding?

So to pick one of hundreds of examples, the money that SCE&G's customers are forced to pay for infrastructure that will never be turned on while the contractors make out like bandits was always going to be scammed out of them by the nuclear industry?

Props for honesty I guess.

I wonder how many people said the same thing about airplanes, or electricity, or any of the countless other amazing things we have accomplished as a species.

Maybe the current trajectory of fusion is unlikely to bear fruit, but we'll learn from it. We may learn something that makes it far easier to implement. A discovery here or there and you change trajectory to something that IS worthwhile.

If you never try, you never get there, you can't see that?

If you do try, you never get there. But you also never get to the other thing that actually has some prospect of working.

Look up "opportunity cost", "sunk cost fallacy", and "good money after bad".

Victorians believed in fairies, very strongly. Their heirs believe as strongly in fusion energy.

Arthur Conan Doyle believed in fairies. Then those who believe in fusion are in good company.

If by "good company" you mean bad company, sure.

A Moriarty man, I see.

Either you have not seen solar parks taking up arable land or you do not understand how this type of land use makes the land unavailable to agriculture. This may not be an issue when those solar parks are built in a desert but it does when they're displacing good farm land like they're doing in e.g. the Netherlands. There are experiments with less dense solar parks and those with vertically placed bifacial panels which should allow combined land use but this has not gotten beyond the experimental stage yet.

Of course it is possible to forego on using arable land for solar parks, only using rooftops and similar constructions for this purpose. Roofs - especially large flat ones like used in industry - are natural locations for PV panels and it is hard to see why one would not install them on new constructions, either on top of traditional roof cladding or in place of it. The same goes for large south-facing walls.

Wind turbines can be placed on farm land without unduly reducing land availability to farming, here the problem comes from nearby population complaining about noise pollution (infrasound, [1]) coming from those turbines as well as 'horizon pollution' [2].

[1] https://www.nature.com/articles/s41598-021-97107-8

[2] https://worldcrunch.com/culture-society/skyscrapers-turbines...

I have seen plenty of land foolishly wasted on single-use solar farms. That does not make it smart. In the future those will find themselves undercut by dual-use farms that continue doing what they did before solar was added.

Rooftops will not be much that.

Deserts are a particularly dumb place for solar farms, but ignorant investors love the idea, so lots of money is wasted on them.

You could be right, and I hope you are. But, given the current state of development in agrivoltaics and such, your prediction has too much certainty.

All power to those projects, but they are really just experimental at this point. Not inevitable.

>global energy consumption is exponential.

From the link:

https://ourworldindata.org/grapher/global-energy-substitutio...

The trend since 1960 appears instead linear. Also, population growth is slowing. But it's fun to extrapolate "exponential" trends and look at the big numbers.

We are many orders of magnitude away from needing to worry about solar using up precious land.

If energy consumption continues exponentially we will cook ourselves.

There's plenty of land for solar, and then there are the oceans, and it's here now. In the medium term we should look at modular fission, and deep geothermal, potentially re-deploying fossil extraction technology.

I'm all for fusion as scientific research, but let's drop the pretense that using it to generate power is remotely realistic for many decades, if ever.

Once you start covering land that isn't a complete desert with solar panels you start competing with photosynthesizing organisms, even more-so with oceans. I don't think anyone expects fusion to be viable within a decade or two. Beyond that I don't know but I absolutely think it's worth funding.

Any amount of primary energy consumption that covers more than the already built up areas or the land currently used for fuel ethanol with solar will rapidly cook the planet through nuclear.

Current primary energy is 18TW. Total insolation is 170PW. GHG forcing is about 200TW. We can provide enough solar with smaller than a 1000km square. More than that will kill us no matter the technology used (but solar is better than most as the total heat it produces is a bit more than the work done rather than 3x).

Growth must end or physics will end it for us. Climate change is the warning shot across the bow, not the full volley.

"Total insolation is 170PW" - That assumes 100% efficiency, it's from the upper atmosphere, and making full use of it would mean there would be no light left for plants or the ocean. After accounting for solar panel efficiency, battery efficiency, and the amount of surface where it's possible to put panels without displacing nature and agriculture it'll be somewhere in the low hundreds of TWs.

"Current primary energy is 18TW" - That's outdated and only consists of the energy converted from electricity. It doesn't include non-electric heating, driving, maritime transportation, aviation and freight. Taking those int account our total consumption is around 100TW.

> That's outdated and only consists of the energy converted from electricity. It doesn't include non-electric heating, driving, maritime transportation, aviation and freight. Taking those int account our total consumption is around 100TW.

That's what primary energy means (as well as the heat wasted from allof the above). My best guess as to how you got 100 is you're mixing up 160,000TWh with TW

> That assumes 100% efficiency, it's from the upper atmosphere, and making full use of it would mean there would be no light left for plants or the ocean. After accounting for solar panel efficiency, battery efficiency, and the amount of surface where it's possible to put panels without displacing nature and agriculture it'll be somewhere in the low hundreds of TWs.

I wasn't implying all of that was available, merely that around 0.1% of that in thermal forcing is enough to be a problem on the same scale as GHG emissions. Wind is the technology which produces the least new heat (none, although if you exceed around 1W/m^2 for too large an area you change the climate in other ways), followed by solar on existing asphalt, grass, or water (up to ~1W of new heat per watt).

Any thermal fuel that didn't recently come from sunlight is in the 1.4 to 3 range (excluding extraction and processing).

This caps primary energy around 400TW for renewables or 200TW for nuclear (with only around 70W as work if you are using a steam engine).

Nuclear provides less end-state access to abundant energy on earth than renewables at higher cost. There is no reason to pursue it.

Perovskite longevity is up to five years, which at the price is already sufficient to be immediately useful in many places.

There will be no fusion.

CFS completed the first of 18 coils on their prototype device last October, and it worked better than expected, far more than enough for commercially viable fusion plants. Their prototype is scheduled to be completed and lit up in 2025, and the first commercial plants should be ready in the early 2030s.

The new high temperature superconducting materials that they're using to build the containment coils make them significantly smaller, cheaper, and less complicated. Definitely worth reading up on if you haven't.

https://cfs.energy/news-and-media/commonwealth-fusion-system...

That is what they tell their pigeon investors. But they don't say there is not enough tritium to operate commercial reactors, or that no material has been identified that can hold the structure together after bombardment with hot neutrons. They don't say that the reactor would need to be maintained using robots nobody has ever built.

Come 2025, there will not be a useful reactor. They will instead offer an excuse, which is easy to come by.

Even if solar and wind can easily supply all our power needs for the foreseeable future and beyond, it would still be worth experimenting with fusion.

If we can get it to work, we will know much more about the universe than we do now, and if we can get it affordable, we will have nearly unlimited power. muahahahahaHAAHAHAHAHHA

er, oops

Why exactly do you think fusion offers "nearly unlimited" power? In any design conceived today, it is in no way impressive in terms of power/plant, and fusion power plants will be the most expensive power plants ever designed (since they are at the extreme limits of materials science and several other branches of engineering).

Exactly - IF we can get it to work, we'll know much more.

And IF we can do it affordably (these are both big IFs), the amount of energy available is huge. I see 1 gallon of water to 300 gallons of gas numbers thrown about; that's huge.

https://www.energy.gov/science/doe-explainsdeuterium-tritium...

(Gotta love their optimism - "when").

As Hamlet says, "It's as easy as lying."

Not "unlimited", but "more than anything else".

We know the energy density is there, based on thermonuclear weapons.

Yes, the designs for a power plant that are similarly impressive don't exist today. That's where research and engineering can help.

Yes, any new thing is expensive. These points are not necessarily intrinsic to the process.

> Yes, any new thing is expensive. These points are not necessarily intrinsic to the process.

It's not expensive just because it's new, it's expensive because it's trying to do a very very difficult thing - using magnets to achieve what the entire mass of Jupiter can't achieve, compress hydrogen so much that it starts fusing, and then keeping it compressed while it's essentially violently exploding - and exploding in a rain of extremely fast heavy particles that don't interact with the magnets at all.

What part of it do you think is intrinsically expensive? The steel? The concrete? The magnets?

All of that requires a lot of capital, but what makes it expensive is the neutron flux ruining it in just ~5 years.

Yes, the steel required to withstand the force of the magnets, and to be dense enough to prevent hydrogen from leaking, magnets powerful enough to contain thebl fusion reaction, cooling systems to keep the superconducting magnets in close proximity to the neutron rain at extreme low temperatures.

These are all the parts we know about. Then, there are all the systems that no one has attempted yet that you will need to actually extract some energy from the whole thing, and to inject fuel into the running reactor, and to recycle tritium.

Overall the reactor vessel has to be built similarly to a high-pressure submarine, but it needs to withstand even higher forces. Not exactly something that can be done cheaply, even though we have been building submarines for a good 50 years.

From my understanding this is almost entirely an engineering problem at this point. The physics behind it has been understood for decades so I'm not sure how much more we'll gain in terms of fundamental physics.

There is still a great deal to be learned about plasma fluid dynamics. Probably the only good that will come out of all the work is a few generations of plasma fluid dynamicists. Pray they can find something else to do when the whole project finally fizzles out.

Well, it's not as if any of them were going to work on solar or wind power anyway, so what does it matter to you?

They are not who is consuming the $billions.

Then why the pearl-clutching over the plasma fluid dynamicists?

Fusion is likely to be useful in situations where renewables are just not feasible. For instance, anything large that moves (large boats, spacecraft, or even aircraft) or has no limited to sunlight (bunkers, deep space outposts, etc).

Fusion, at least of the most commonly pursued DT variety, is terrible for mobile applications since its power density is so low. The ARC reactor concept (190MW(e)) weighs as much as several WW2 destroyers.

I'm going to go out on a limb and guess they modern fission plants that are not designed with portability in mind also have really low power densities. Just imagine the weight of the cooling towers. And yet, very different designs with different requirements can be made to fit in a submarine.

I'm not saying it's going to be possible to run container ships on fusion, just that using a fixed research reactor as a data point probably isn't very useful.

Actually, no, fission reactors have much higher volumetric power density. This is inherent in the technology -- in a fission reactor, coolant flows through the core, with large surface area for heat to transfer from the thin fuel elements. In a DT fusion reactor, the coolant has to flow in a blanket around the core, and all the power has to radiate through the surface of the reactor itself. The square-cube law comes into play.

Doesn't fusion still require vast amounts of water to turn to steam?

“Nuclear fusion is 30 years away; and always will be." I wonder how this phrase manages to hold after 50 years since its inception.

We could compare it to the state of general AI, but at least in the machine learning field, progress is being made without knowing the feasibility or path to reaching general in AI. In fusion it appears that the theory has already been set and maintaining the chain reaction going for long enough is the limitation (progress being made here), would it be the same case that the final steps are still missing without a clear path, or would the current progress be enough to eventually reach it?

AI research has made slow scientific progress but great engineering progress. Fusion has made great scientific progress but still has a lot of engineering left to do.

> has made great scientific progress but still has a lot of engineering left to do

It’s made serious engineering progress too.

Engineering work halted 30+ years ago. There has been no recent work on structural materials that could withstand the neutron bombardment, and no work on extracting bred tritium at parts per billion concentration from thousands of tons of "blanket" material needed for the next day's operation.

There is no possibility of any present scheme operating at even 10x the cost of fission. Fission is not today competitive, and falls further behind each day.

You can get around the tritium problem with boron-proton fusion. Also gets around the inefficiency of converting to heat / turbines. Obviously not any closer to production (and probably further) than tritium fusion, though. https://hb11.energy/how-it-works/

There is no reason to expect that p-11B fusion is possible.

It might be, in a hundred years, if our present understanding is wrong, and somebody figures out how to reflect gamma rays.

It's been done by firing lasers at a HB pellet, so I assume you mean not possible to be done commercially? And why would you have to reflect gamma rays?

Obviously you can fuse about anything by accelerating nuclei at each other fast enough. If it takes more energy to do it than you can get back, it is of purely academic interest. Firing lasers comes up many orders of magnitude short.

Another alternative is magnetic confinement, but radiative loss goes up with the 4th power of temperature, so would be 10000 times as much as for a D-T plasma, IIUC.

Are you talking about the company H11B?

Their scheme has been soundly criticized in the literature as not working by a factor of ~100.

> Engineering work halted 30+ years ago. There has been no recent work on structural materials that could withstand the neutron bombardment

We've made massive strides compacting designs, thereby transforming their unit-economic envelope, using low-temperature superconducting magnets. Those magnets continue to improve, driving potential gains in designs faster than experiments can be funded and built. Optimizing for structural materials, or even blanket versus replaceable structure, seems premature when we don't know the parameters or even type of bombardment we'd be working with.

Bombardment is with hot neutrons.

Period.

Timeline of Nuclear Fusion : https://en.m.wikipedia.org/wiki/Timeline_of_nuclear_fusion

This chart rests upon faulty assumptions about the efficacy of tokamaks, but it does demonstrate how little interest the U.S. federal government has had towards research of fusion.

http://i.imgur.com/sjH5r.jpg

https://hardware.slashdot.org/story/12/04/11/0435231/mit-fus...

Why did we have to polarize nuclear and renewables??? Why can't we just aggressively build out and develop both and leave it at that? There is money and resources enough to accomplish both, but as a society we just choose to allocate our time and efforts on stupid bullshit. If people are serious about fighting climate change (which I don't think very many peole are) then we need to Manhatten project the solution. A 'war' needs to be declared and some drastic lifestyle changes need to be made by most of the world population. Everyone talks about nuclear and renewables as if it can only be one or the other. I don't ubderstand this sentiment on HackerNews.

I think that HN is strong in software development areas but those people usually don't have a solid understanding of engineering topics. Using slightly different assumptions, data and mental models you can come to totally different conclusions. Then these energy topics have been heavily polarized by different interest groups for many decades and sophisticated falsehoods are being promoted. I think it is much easier to start with a conclusion and then to build an argument by selecting data than to go the other way of trying to understand all the different alternatives and their impacts. None of the energy sources is ideal in all the ways you can look at it, none of them is a clear winner over all the others (even though it may seem so if you have a simplified understanding).

We need to cut through the BS and invest in at least one of the viable solutions. I even think that we can invest enough in all of the viable solutions and then some. The money we are spending on nuclear fusion is still peanuts compared to the whole picture.

The "Manhattan project" style approach will happen once our platform is really burning but that may be many years into the future. I'm hopeful that solar and wind out-compete fossil fuel economically and gain enough traction that way.

There isn't enough money to replace the current system with fission, it's simply too expensive.

Ask that to ecologists, pro nuclear people don't care if renewable are used in combination with nuclear, but pro renewable are very adamant about the fact nuclear is bad and shouldn't be used at all

Take germany, they prefer to guzzle on russian gas or choke on coal fumes rather than admit they fucked up. They've been lobbying against nuclear for years and now they blame france for their electricity issues: https://www.politico.eu/article/germany-set-to-extend-nuclea...

Can someone explain to me the 2nd order effects if we made energy 10x cheaper? Do we ever have to worry about waste heat? I'm not an EE or physicist (maybe in retirement).

I am also interested by this question. Energy => machine/labor => GDP So, my first naive take would be that we could extract/build/ship more for less, and then potentially keeps the "growing" economy humming.

Maybe due to my past education/experience, I still feel uncomfortable about more waste (if energy is cheap, why not like in Quatar build stadiums with AC ? keep AC stores doors open in summer, and in winter when the heat is on, etc.)

I have a sense that increasing energy waste will come to 2nd order cost on other resources (water, minerals, etc.). Thoughts ?

At least for a while fusion isn't about being cheaper.

It's about being abundant.

Neither one.

There is no world where fusion would be more abundant without being cheaper. Sure, it's nice that you only need water to get half the fuel of a fusion power plant, but even for fission, uranium is a fraction of the cost. The reason fission isn't already providing us with abundant power is the huge cost of the extremely advanced fission reactors - which look like lego blocks compared to a fusion reactor.

And 1 fusion reactor will generate nowhere near the power of the largest fission reactors we already have, in any design considered realistic today.

Not to mention, the extraordinarily expensive fusion reactor you build will become too brittle to hold itself up in the span of 10 years at best, because of the neutron bombardment - turning your massive investment mostly into highly radioactive waste that you'll need expensive robots to disassemble and replace.

Resistive heating for homes in cold climates becomes economical, so many can more easily move off of natural gas / propane in northern climates.

Battery advancements and supply logistics become the only holdup to clean transportation (right now, there isn't sufficient renewable generation or storage to completely replace fossil electricity).

Atmospheric CO2 scrubbing becomes more economical, so waste heat is not an issue I suspect.

Completely moving off of fossil fuels makes petroleum extraction much more expensive, as the primary products are not used as much, so anything currently relying on petroleum (plastics, makeup, asphalt, etc etc) becomes more expensive until renewable synthetic production becomes mainstream.

"However, the long-term (hundred years) global warming by CO2-caused radiative forcing is about twenty-five times stronger than the immediate effects, being responsible for around 92% of the heat-up caused by electricity production."

https://www.sciencedirect.com/science/article/abs/pii/S03605...

This seems to be in the ballpark, although the podcast "methodisch inkorrect" cited (years ago and in german) a perhaps too ideal number of 99%.

Lets agree on a factor of 20 between burning fossils and using fission as an energy source for a further guesstimate.

Solar and wind are better than that, since they have primary energy requirements for production, but no warmth is generated: the albedo of solar panels is as good as grass, the warmth generated by a wind turbines would be generated by the wind slowing down on a tree, house or mountain as well.

As which is cheapest, that could vary between those three technologies. None are regulated as fast as gas turbines, but fission power output is perhaps faster to scale than fusion or even coal.

Having energy at one tenth the cost (solar/wind is supposedly already half to on fifth to cost of fusion) we could feasibly consume ten times the energy by replacing fossils, traveling more, consuming more and giving 80 % of mankind the final lift to 90s-level western accommodations.

So perhaps no net change at all in the ecological balance of heating our space ship if we really switch to fission and keep the our mind set on growth by more technology.

It will never be 10x cheaper, at least not to you. Half of the cost of electricity is from distribution costs. So even if it was completely free to generate electricity, it would only reduce your bill by half.

Extensive deployment of renewables is already changing the grid substantially. Smaller grids with more local sources may be cheaper than the large generator and grid model that has so far dominated.

Of course greed ruins everything but part of the distibution cost is paying for energy (to make equipment, transport it around, feed the people involved, etc.)

It gets a lot cheaper all of a sudden if you have space for 10kW of solar, 2 weeks of storage and tell the distributer to go f themselves

Fusion will absolutely not be "10x cheaper", in any possible circumstance. Rather, it would necessarily be at least 10x as costly as fission; and fission is not now competitive, and gets less competitive all the time.

Solar and wind cost are still falling sharply, so you may well find power substantially cheaper in the future. There won't be any fusion plants at all, because no one will put up money to build any.

There will be a fusion plant in space, because to build an interstellar vessel you need a source of power that is not dependent upon wind (which is absent in space), nor solar (which decreases in power the further you are away from stars).

Unstated premise: there will be an interstellar vessel.

Unstated premise: you can't use a fission plant.

By the time a proper interstellar vessel is to be designed, we will no longer be dependent upon the hoary '50s plans of Project Orion.

There's no need to fling bombs; much better to just superheat gas and expel it.

Energy is about to become 10× cheaper, thanks to the rapidly advancing state of PV, wind turbines, and batteries. There is no problem of waste heat with these.

Some obvious things: carbon capture and storage, synthesis of plastics from air-captured carbon, large-scale desalination.

We'll know at least some other new applications in 2070 - 2090. One possibility is direct synthesis of carbohydrates and amino acids from the air.

Not until 2,500 at current energy growth rates.

The real question is no if it's the energy of the future. The real question is it going to be in time to save us?

Even if we knew exactly how to make fusion reactor today, how long would it take for it to effectively replace all the fossil fuel energy? Too long is the answer.

> The real question is it going to be in time to save us?

From what? Global warming? No, it won't.

If somebody creates commercially viable fusion today, it will still take some 3 to 5 decades until it is common enough to impact our energy generation. And if it is based on breeding Tritium, those 3 to 5 decades are dictated by physics. (But just the ramp-up on constructing those power plants is enough of an issue, no fundamental physics needed.)

I personally believe that nuclear fusion is a necessity for long-term survival of humanity -- I'm talking centuries out.

I am not a physicist (humble startup dude / engineer / sales guy). Is there anything someone like me can do to contribute to this space?

Tell people about General Fusion and invest should they ever go public.

Talk to rich people and convince them to invest in the space instead of buying bunkers in New Zealand.

Explain to people around you. Eventually this has to percolate to the government. It is a question a national security, for every country. If a country wants to secure its GDP, then it needs cheap energy.

Oil has been the primary cheap energy, but burning something that takes thousands of years to make, is not sustainable. Even ignoring that fact that transferred all those carbon from deep underground to the atmosphere, and changing the climate of a couple degrees Celsius in a century, when it took 100,000 years get over the last glacial period that was just +5 degree Celsius. And now we just added 1-2 degree in likely less than a century. The last glacial period ended 15,000 years ago and allowed human settlement. So 5 degrees completely changed the geography of the world. Not sure what the next 5 degrees would do to our civilization.

All countries on earth need access to cheap and sustainable energy to support 8B humans. To feed them and protect them from the weather.

As a blunt reminder. If the gas production stops unexpectedly, big cities die. Like people have to leave the city or literally starve to death. A city like NYC, with 8M mouths to feed 3 times a day (3x~2,000 calories), if trucks, boats and even trains (diesel) are not moving, I doubt the city could survive a week. Cheap and accessible energy is paramount for our current local and global economy.

Been hearing a lot of fusion hype lately. Guess it's that time of the decade again..

The pigeons need to be gulled again.

Current proposals for nuclear fusion, most notably hydrogen fusion variants (ie deuterium-tritium in particular), increasingly seem like a pipe dream to me. Fusion seems attractive because stars do it but stars also have gravity on their side. We hafve to build lmeter thick concrete walls to protect against errant neutrons (as mentioned in the article) but that doesn't solve the real problem: escaping neutrons are energy lost.

You also can't ignore the fact that those neutrons also destroy the precise equipement designed to contain the reaction.

Add to this, you need to perfectly contain an ultra-high temperature plasma and you run into fairly fundamental issues with fluid dynamics (ie turbulence).

I'm disappointed but not the least bit surprised that the pro-fission HN crowd tries to hijack this thread into a fission energy argument. Is it possible to discuss nuclear fusion without bringing the quite unrelated fission issue into it?

There is also the problem of extracting grams of tritium every day from a thousand tons of lithium "blanket" so you will have fuel to operate from tomorrow.

But the biggest problem is no one will pay more than 10 cents for what costs you dollars to produce. The fission people hold out hope that people can be forced to pay 50 cents for what they can get for 10 elsewhere.

There are some potential down sides to fusion power. One is that it may make huge energy releases possible. Think releases of heat that physically warm the planet (instead of messing with the atmosphere and causing heating indirectly). Another is that it may enable some machines to run for a very long time, particularly if it becomes well understand enough to make small fusion reactors. Like a robot that remains powered for years, or a tank that runs for years, or a plane that can fly for years (and aircraft carriers, and chemical plants, etc.) Right now it would be very difficult to make a machine that could slowly destroy the world, perhaps by mining and releasing poisons or turning the air into ozone. A fusion powered machine could toil away for a decade with no need for fuel. These are not near term risks, but they are risks none-the-less.

Are these your personal speculations or do they have a reference?

Personal speculations, but it seems obvious that the raw amount of energy available to civilization would increase dramatically in the long run. What are the consequences of that? They are not necessarily all good.

LOL, sorry but this is bull.

The Sun is hitting the Earth continuously with about 173,000 TW of power [1].

Even with the most optimistic sci-fi scenario with 24/7 nuclear power for everybody on Earth, it would be barely noticeable.

1: https://news.mit.edu/2011/energy-scale-part3-1026

Sure, but how much heat would it take to tip an ecosystem into collapse? Someone could build a fusion plant that just creates CO2 for a decade out of seaweed or something. What I'm saying is that the scale of power available to us would be changed, and there will be consequences to that. Some good, but not many people seem to be thinking about the potential bad consequences. Maybe we could melt glaciers to get drinking water, would that be a good thing?

We are far, far away, from being even a rounding error on that massive amount of energy.

Also, all energy generation eventually ends up being heat, it's not like fusion does it but not the others.

Yes, insolation is 173 PW. Trying to intimidate with big numbers doesn't make you any less wrong.

Current primary energy is 18TW.

Current GHG radiative forcing is 200-600TW

Everyone living like americans on fusion energy (180TW) is sufficient to be as bad as GHG climate change would be with 90s level emissions.

Everyone taking your attitude would see us back exactly where we are now in a few decades.

PV on asphalt or building has little to no net albedo change. 1W of PV on water or grassland produces ~0.5-1W of heat now and 1W of work-becomes-heat that the dark surface would create anyway. With the advent of tandem cells this will go down to being relatively insignificant. Wind is energy that would thermalise anyway. PV on desert or snow is a concern.

Steam engines from stored fossil fuels or nuclear produce 2-4W of heat (depending on fuel enrichment or extraction/mining inefficiency) and 1W of new work. Magical fusion technogies are at best like PV on water.

>Everyone living like americans on fusion energy [...]

That argument is true for any source of energy, not just fusion. Fusion, at the very least, doesn't produce a GHG byproduct.

You can't just ignore the rest of the comment. A solar panel placed above existing asphalt creates no heat (merely delays the transformation of a watt of light into heat via some useful task) whereas a watt of work from a thermal fusion plant creates at least three watts of heat (but likely more).

It is also a reason why solar and wind is enough. We do not get to use more energy than they can provide while covering <3% of land without needing to geoengineer the entire planet anyway.

Finally the vast amount of steel and exotic materials in the fusion reactor which will only last a few years before needing to be buried for a century requires strictly more GHG than the renewables that would do the same job.

It solves no real problem other than to handwave at 'abundance' which cannot be achieved on earth anyway and has massive downsides.

Everyone could live like americans (at least energy-wise) on renewables. We couldn't go much further than that, but 0.5W/m^2 of wind and 1% of the land area with solar panels would not cause too much impact on the world. We cannot do this with any other energy source (excepting maybe tidal)

You're right and I agree with you that PV is the best bet.

I'm not sure I'm following what the implied subject of what it's a best bet for (unless you've changed your mind vs. your first comment and now agree we're within a factor of 10-30 of thermal forcing being important?)

We're already capable of huge energy releases using fusion. And also of machines that can run for decades with nuclear power, both via rtgs and just fission.

Fission powered machines could do the same and we haven't seen them proliferate, in fact, quite the opposite. A mobile fusion powered device would certainly be harder to make than a fission powered one.

  "Star machines", "This form of energy ... will be abundant, efficient, carbon-free, safe", and "solve all of humanity’s energy problems in one fell swoop – amongst many other things. "

Humbug.

Even if/when it is possible to build a power plant (many decades IMHO) it will be massively costly, the waste from D-T fusion is far more of an issue than is being discussed, the efficiency will be terrible, barely enough to make the thing workable, etc.

  "Tritium… can be made from another element that is extremely plentiful: lithium."

So we're going to burn all the lithium, instead of building batteries with it?

Doesn't really matter, as we can also build batteries with sodium, calcium, aluminum, iron, zinc, and with carbon polymers. And probably more.

There is plenty of lithium, but we won't be burning any except in H-bombs. We may hope not there, either.

If we don't fend off climate disaster, there will be plenty of that soon enough.

> So we're going to burn all the lithium, instead of building batteries with it?

There are lots of reasons DT fusion is stupid, but this isn't one of them.

If you made a 1kg lithium battery and filled it with DT fusion from one kg of fuel then you'd have to wear the battery out after filling it thousands of times and recycle it 10s of thousands of times.

If you lost 100mg each time you recycled your 1kg battery, you'd run out of battery long before the fuel ran out.

The massive resource consumption of fusion comes from burying the 10000t reactor with 100s of tonnes of materials much more exotic than lithium for 100 years after running 100kg of fuel through it

The amount of anti nuclear from a few accounts in this thread is weird and reeks of weird concern trolling.

It's mostly from one person, who somehow gets away with (up to) dozens of low-effort comments on every single story about nuclear power. I happen to agree with their basic premise, but still find it highly suspect that such spammy behavior continues to be allowed.

They seem like a concern troll-for-hire type of thing tbh. I find it concerning that they're allowed to continue to be here too

In my own case I'm just trying to get people to let go of the idea that nuclear (fission or fusion) is viable for electricity generation.

Please read the paper by Way, Ives, Mealy and Farmer[1], look at the trends, and draw your own conclusions.

Edit: as I said in another comment: It's 1972, the microprocessor has been invented, and these guys are saying "what the world needs is much bigger mainframes. Much, much bigger."

1. https://www.cell.com/joule/fulltext/S2542-4351(22)00410-X

Looks like there's a discussion thread here.

https://www.reddit.com/r/RenewableEnergy/comments/xeydwp/emp...

Thanks for that. The main criticism is that "it looks like a curve fit". Indeed it does; the paper talks at length about this very thing. (Mostly in the 400 page supplementary paper S1.)

But the thing is, the curves (Moore's and Wright's) apply to a lot of technologies undergoing rapid expansion. That's actually the science contribution of the paper: setting out a better way to make policy-relevant forecasts, and hopefully ending the abysmal track record of forecasts that is documented in the paper.

(I can see ways to get at least 67% cost reductions in both wind and PV from where we are now, and I'm just an interested layman. So in at least the near term we will likely keep following the curves. Yes, actual work has to be done, but there's no voodoo. Just like with microprocessors.)

Won't live long enough to see the answer to this but really curious if very cheap power leads to (much) lower cost of living for the masses or rather is used by nations to power their war-machines and make war cheaper/more frequent.

In the third image you can see it's built with Python.

See "The tokamak hall at Culham"

We are much more likely to solve the large scale battery problem than the fusion problem in some reasonable timeframe within our lifetimes.

Once we solve the battery problem solar and wind become enough to power humanity.

Honest question: doesn't the production of battery and photovoltaic cells require quite an investment of rare elements and significant carbon emission?

They last 20 years though. The investment pays off over a long period.

not just a cost question but a resource availability/energetic cost of resource extraction question.

If it takes more and more fossil fuel use to extract the increasingly rare components of the renewables, then renewables may not be able to save us.

I don't know if it is true, but it is a legitimate question which is worth knowing the answer to...

There are no "increasingly rare components".

So, no, it is not any sort of legitimate question. It is, rather, concern trolling.

My guess is he's talking about Lithium and if so that's not concern trolling, Lithium mining is very expensive and if we want to go full renewable we'll need some major storage capacity. There's obviously ways around that, hydro storage being the most obvious, but it is something to think about.

The question was too vague to guess what it was about, if anything. It presupposes there is some resource used for renewables that is scarce and for which there is no viable substitute. Without identifying any, it is just trolling: there must be trouble somewhere, what can you come up with for me to carp about?

Lithium is about electric cars, not about renewable energy production.

To the popular imagination, it is easy to make a popular misconception linking renewable energy to rare earth minerals, because for good or for ill electric cars are a dominant facet of green technology. There is a not uncommon narrative that "electric cars are actually bad for the environment because they require scarce metals." News stories abound.

https://www.reuters.com/article/us-metals-autos-neodymium-an...

https://www.forbes.com/sites/kensilverstein/2022/02/06/the-f...

Rude pedantic ill-tempered dismissals of conversation as "carping" discredit a good cause more than a thousand fusion startups do. Perhaps if you want to win hearts and minds, engaging in both education and a little empathy would do wonders for your position. And to the betterment of the discourse hereabouts.

"Rare-earth" metals, are not, in fact, scarce. Insisting otherwise is misinformed at best, or disingenuous in your case, because you have already been told otherwise.

I am misinformed. But you are impolite.

A gram or so of silver per kW is the rarest component of PVs, and the total ammount of (recyclable) silver per year the PV industry uses is going down even as production increases. The copper is less than a commensurable amount of steam generation. Silicon refining energy is a hundredth or so of output and declining rapidly steel in a nuclear reactor outmasses the silicon and has a lower but rapidly closing energy requirement. Frames can be aluminium or even wood. The glass outmasses steel in a nuclear reactor, but not concrete, and has a lower carbon footprint than concrete and is reusable.

Wind uses copper and niobium, neither of which are essential to the concept. The copper is currently more than steam generation, but some can and is being swapped for abundant aluminium. Magnet free stators are being worked on extensively and are close to cost competitive. Steel use of the largest turbines is competitive with nuclear so iron alloying materials are a wash.

Nuclear uses zirconium, uranium, cadmium, silver, and a variety of other exotic elements as well as the copper for the steam turbines. It is difficult to find out how much, but back of the envelope (0.1% of the fuel assembly being control rod so 0.2g/GJ) would indicate it's more constrained by silver and cadmium than PV is by silver. Plus it is high level waste at end of life and you need it all up front.

The only question is whether the concrete in wind is worth the CO2 as this is the only resource where nuclear wins.

No and no. Solar panels use a little bit of silver and more copper, and no rarer materials.

There are numerous battery chemistries. None competing for utility-scale use involve any rare materials or substantial carbon emission. Likely chemistries include iron/air, zinc/bromine, and manganese/calcium.

And the overwhelming majority of utility storage built will not be "batteries" at all. Compressed air, liquified air, synthetic ammonia, electrolysed hydrogen, pumped hydro, and buoyancy will probably all be used in various places. Just now, almost all is pumped hydro.

Most future storage will be constructed after the majority of energy produced is from renewable sources.

> significant carbon emission

What is significant?

Photovoltaic panels take around 1/30 of the energy they provide to build (that number is constantly going down). So if you replace all of our energy production in one go, it will take about 1 year of pollution to create them.

What is obviously a crazy idea that will never happen in practice. On the real world, the panels are produced more slowly, and are replacing the most polluting energy sources first.

(Batteries, by their turn, do not need as much energy to create.)

I imagine OP means the mining and production of batteries at grid and transportation scale will require an enormous amount of energy expenditure and resources.

Most storage will not be batteries. Most energy expended building storage will be from renewables.

There can be a saturation a point where that becomes true, but I can’t see how that’s possible upfront.

Virtually all of the national and global manufacturing and logistics is fossil fuel driven.

I’m not saying it shouldn’t be done but unchecked and without care our industries will take shortcuts and warp good intentions (like ethanol).

Most storage will be built after there is renewable capacity to charge it from, therefore available to build it with.

I can see it if it’s purely domestic end-to-end.

But at least in the US, we have a bad habit of outsourcing our problems away: Out sight out of mind.

If there’s any significant portion of the build out that’s non-domestic, then I have reservations.

Nobody gets a price break on their power bills when they make panels or batteries, and nobody pays for it and fails to pass on the cost.

Every single kWh that goes into making any piece of kit, whether battery, wind turbine, solar panel, e-car, or what-have-you goes onto its price tag.

I don’t mean price breaks.

How does one account for manufacturing and mining that is offshored, to ensure that they don’t use fossil fuels (like coal) in their process?

It’s the manufacturing analogue of organic food certification.

If you have any pull, feel free to liberally use this as your own :)

By the time much storage is being built, renewable power will be the cheapest choice, by far. So, you are worried that somebody up the line will choose to use expensive fossil-generated power instead of cheap renewable power.

Just by preferring the cheaper product, you bias your choice toward being made with renewables. It is not a guarantee, but in aggregate it is good enough.

That's the thing. Highly optimized portable batteries need some expensive materials, but stationary ones do not.

There is no reason for them requiring enormous amounts of energy, unless your definition of enormous is a trainload.

It did, but it does not any longer. Lifecycle estimates vary from 5x worse than nuclear to 50x better for solar and 5x worse to 5x better for wind.

At 30c/W, even if the only activity required to make a solar panel were dumping anthracite on the ground as you mine it and setting fire to it you would still get more energy per kg of CO2 than gas.

The raw materials are sand, are copper and silver for current PV tech with trace amounts (milligrams per kw) or dopants. The amount of silver per panel is decreasing faster than the rate of panel production is increasing. Copper is mainly for wiring up and can be exchanged for aluminium if scarcity and thus cost is an issue, and inverters require substantial amounts of exotic materials (but less per capita than a phone or laptop).

A nuclear reactor requires more steel than PV requires silicon, and commensurable amounts of exotic materials.

Wind turbines require about the same amount of steel as nuclear but substantially more concrete.

There is no "large scale battery problem".

Energy storage is a simple matter of civil engineering: a big job to construct enough, but requiring no new technology.

We are not building it now because it would be stupid to build storage there is no renewable capacity to charge up from. Money is overwhelmingly better spent today on renewable generating capacity.

By the time we need to build storage, it will be much cheaper than if built today.

Large scale storage is not cost effective with current tech. It is not just a civic engineering problem.

Solar power is very cheap, but a complete 24/7 solution requires batteries. Those are much more expensive than the panels. A better battery is all we need. Panels are good enough already.

The overwhelming majority of storage used will not be batteries, unless some new chemistry's cost is very low.

Large-scale storage will be very cheap, on par with panels. It really is just civil engineering. Any competent civil engineer can sketch a practical, cheap storage system using only century-old tech.

Hand-wringing over utility-scale storage amounts to concern trolling.

What kind of tech would be used for storage?

Not the OP but dams and resevoirs is what he is talking about, I assume. Pump water uphill while the sun is out, let it feed back downhill and generate power overnight. It is century old stuff and it is very much validated to work.

There are numerous practical methods.

Not the person you're replying to but pumped hydro is the most primitive I know of.

Also: why must the highly variable renewables share the grid with highly variable demand, use them to make hydrogen (only when the sun is shining/wind is blowing), feed that into a totally separate power plant, simple to manage - if renewables really get cheap who cares if it's inefficient.

Hydrogen will be one storage medium, mostly stored underground where geology favors it. Tanked anhydrous ammonia will be common, with more ordered from tropical solar farms when local tankage runs low. Underground and underwater compressed air will also be common. Liquified air might be.

In addition to pumped hydro, you can use flywheels or even lifting heavy weights really high up.

Probably neither of those will find substantial use.

For medium duration storage (days to weeks):

https://en.wikipedia.org/wiki/Compressed-air_energy_storage

https://en.wikipedia.org/wiki/Metal%E2%80%93air_electrochemi...

For long duration storage: hydrogen, ammonia.

> Once we solve...

Why do we act as if it was just a matter of time ? It might not be solvable, or economically solvable

It's already solved insofar as a fission or fusion heated steam engines can be solved.

Pumped hydro and caes is scalable at lower prices than fission could achieve. DT fusion will be much lower power density with much more exotic materials and much higher maintenance burden.

It's just that renewables have to live in the real world where customers aren't strongarmed into paying $200/MWh for 50 years to pay for them to do whatever they want. As such work needs to be done to make solar/wind+storage economically dominate gas because governments are not powerful enough to make fossil fuels pay for their externalities.

Did this page hijack anyone else's back button? Weird.

Not for me, no.

There is an old joke that physicists like to wheel out every now and then. It goes like this: fusion power is just 20 years away and it always will be.

What I want to know is why nobody talks about this.. https://brillouinenergy.com/news

> Researchers at SRI International have issued a Technical Progress Report covering their review and independent validation of Brillouin Energy’s on-going testing and scaling efforts of its most advanced Isoperibolic (“IPB”) Hydrogen Hot Tube™ (HHT™) component prototypes, which generate controlled Low Energy Nuclear Reactions (“LENR”).

I've been keeping an eye on it since 89 and this seemed significant.

It's probably because they appear to be cranks who keep promising results right around the corner and never deliver.

Here's a story from 10 years ago about how Brillouin's technology can generate electricity for 1 cent per kilowatt hour, linked from their official blog at the time [1]:

https://web.archive.org/web/20130515012248/http://pesn.com/2...

If they had an empirically working device, by now they could just be using it generate heat and/or power and leave it up to better-funded institutes to figure out the mechanism after the fact. Since they're not selling the devices and they're not selling power, and they've been "iterating" for years, I don't think that they actually have anything.

[1] https://web.archive.org/web/20130421190244/http://brillouine...

Making empty promises about fusion tech is a good way to collect investors' money with no risk of fraud indictments, and no need ever to pay any back.

Work done under government grants is similar.

Tbh it was only the SRI confirmation that caught my eye.

I've mostly written this off but was curious what the relevance of it was as it did seem to be verified by an independent body. The question of if the tech can actually be used for power generation..no idea but never seemed likely.

It's 1972, the microprocessor has been invented, and these guys are saying "what the world needs is much bigger mainframes. Much, much bigger."

You owe it to yourself to read the paper by Way, Ives, Mealy and Farmer in Joule, "Empirically grounded technology forecasts and the energy transition". Or at least look at the pictures.

1. https://www.cell.com/joule/fulltext/S2542-4351(22)00410-X

Are we talking like Nutty Professor levels of big? Should we be concerned about how big the scientists are getting?

The scientists are becoming enormous. Even inflation fetishists are beginning to voice concern.

What are the inputs and outputs of most potential fusion energy projects?

Fusion is the energy source of the future, and it always will be.

Helion energy?

This is the only fusion project that could conceivably have a future.

It really isn't.

First they're openly lying about how they get energy out. Only a tiny fraction will come out via their EM coupling, the rest has to be recycled via a heat engine at massive loss even to keep it running. They tell you this indirectly in their press releases but then go on to say that the EM coupling solves the problem.

Then there is only enough potential He3 prpduction worldwide to provide 10% of primary energy for about a minute per year. The overwhelming majority of this of this is a gas mining byproduct. Lunar mining might be possible, but the sheer volume of equipment needed means it's just really complicated and inefficient methane or oil power.

p + B fusion might not be pure scifi, but noone has demonstrated any compelling evidence.

If any of the options have a real application my money is on the general fusion concept purely because it separates the stuff that has to stay the same shape from the stuff that can melt anything by a blanket of liquid metal. I can't think of what that application might be (maybe surface area limited applications like boats? Seems like it's a massive proliferation risk distributing easy neutron sources though).

They would produce their own 3He via DD.

Explain how you know they are lying about energy recycling?

> They would produce their own 3He via DD.

So solve the problem of fusion producing neutrons which wreck everything by producing neutrons which wreck everything?

> Explain how you know they are lying about energy recycling?

They brag directly in their promotional videos about recovering the 'remaining' thermal energy in their plasma via a heat exchanger back into their magnets.

The second you run your energy through a heat engine twice, you've lost. The entire concept can never be commercialized.

That's even if you haven't built a multi billion dollar boondoggle that will fall apart in ten years due to neutron embrittlement.

DD neutrons are much less damaging, as they produce far less helium by (n,alpha) reactions than DT neutrons. The D3He reaction produces no neutrons at all.

The reactor is cylindrical rather than toroidal, and doesn't need to breed tritium, so one could imagine this neutron absorbing shielding being something that could easily be slid out and replaced, if needed.

No, they are not recovering remaining thermal energy "by a heat exchanger". They are allowing the plasma to expand against a magnetic field, doing work, which is collected as electrical energy. I've been told they reported 95% efficiency at recovering the energy of compression by this means.

After doing some reading I was definitely wrong about expanding and cooling implying thermalising. And they do seem to be doing real engineering around problems you'd only think about if you had something that worked.

I'm still not convinced it's viable (largely because they are acting exactly like scammers for some reason -- perhaps peer pressure?), but I cannot find evidence of the same deal breakers as DT or fission.

I went through a similar process with them, thinking it didn't work for a reason, then finding out the "reason" was the product of my own misunderstanding.

Reply on news.ycombinator.com