Similar to how energy is extracted from fission reactors currently: the heat is used to boil water which makes large turbines spin and produce energy. It's dumb engineering. (I don't mean that in a bad way.)
Despite the 'but', I don't think you are disagreeing with your parent (who I took to be saying that they found it slightly amusing that we haven't discovered any more efficient ways to turn heat into electricity). If you meant that steam turning a turbine is the most efficient way that we know to turn heat into electricity, then it seems that you're saying the same thing as your parent, and it's not clear what 'just' adds. If you meant that it's the most efficient way that exists, then, first, I wonder how you know; and, second, I think that far from this being 'just' anything, it's pretty remarkable that we stumbled on the literally most efficient possible way so early in our history of working with electricity!
Saying the best way we know is the best way we know is vacuous. Nothing about steam is especially good except that water is cheap. It was cheap before, and still is. Its problems are problems we have learned to live with.
But it costs more than wind or solar, even with free heat. So it is a dead end.
You are right; I missed "that we know". That is entirely my mistake. But then it seems to make gridspy's comment rather content-less.
If someone says "I always find it slightly amusing how there's remarkably few forms of power generation that don't eventually boil down to "use water/air/steam to make a turbine spin".", then what does saying "it's just because that is the most efficient way we know" contribute? The 'because' suggests some justification, but it appears just to be re-stating what it's justifying. A re-statement can be valuable, but combining it with 'just' seems to be dismissing an observation that I, at least, found interesting enough not to dismiss, even if it is 'just' a description of existing facts.
So what I thought I was contributing here was an explanation of why we like steam and turbines so much.
I'm pretty sure that steam, turbines, etc have a big efficiency loss. Like you guessed, I meant "the best way we know of to do it at industrial scale now."
I see what you did there. I feel the same way, though. It feels primitive. But it’s what we’ve got!
"Though most commercial panels have efficiencies from 15% to 20%, researchers have developed PV cells with efficiencies approaching 50%."
"Both nuclear and coal plants show a range of efficiencies. Nuclear plants currently being built have about 34-36% thermal efficiency, while one of the new reactor designs boasts 39%. In comparison, new coal-fired plants approach 40% and CCGT plants reach 60%."
For PV, a higher "efficiency" means less land is used for a given nameplate power output. Desert land is not in noticeably short supply, though.
Or it might mean that PV is economically feasible in high-latitude or chronically cloudy areas.
A weir way uphill with a penstock and Pelton wheel could do better than the old mill, but both depend on landform features with limited distribution. If you needed twice the power, you would be stuck. But you can put out more panels.
Even in my relatively wet and grey corner of the world, I'm confident that if I spent $X on PV vs hydro, the PV would produce more electricity and require less maintenance.
PV/wind turbine efficiency and Rankine cycle efficiency are basically entirely different concepts physically and economically. Highly efficient rankine plants might turn 35% of the potential energy of expensive nuclear/coal fuel (which costs money) into electricity. In the process they produce waste heat and waste (dealing with those things is typically kicked down the road). Solar turns 20% of something that is free (being pointed at the sun modulo land use) into electricity with zero waste and zero additional waste heat. How is that inefficient (even if it were half that)? You can and should say lots of things about scale or nighttime but none of those have to do with prime mover efficiency.
Now consider economic efficiency. The denominator of economic efficiency for solar/wind is financing charges and the numerator is multiplied by a lower capacity factor whereas for everything else the denominator is financing charges plus fuel costs. Fuel costs are expensive and boom/bust volatile creating huge economic uncertainties. These uncertainties increase financing charges further reducing economic efficiency. This is before you get to waste or waste heat.
I don’t think 100% solar is a realistic option but neither are baseless claims of inefficiency.
> I don’t mean to be rude, but to say this without qualification is essentially baseless ignorance or lying.
Your own words can be used back at you.
(Not agreeing with GP, but your zeal in rebuttal falls victim to your own accusation)
We're their pet project, why would they invade?
Or if we let off some earth mammals the beasts would be like, you know what, humans, take me and my descendants ten/a thousand generations down back to earth.
This sounds awfully knowledgeable about travel over multi-generational distances when neither you, nor I, nor any other human has ever done it. Maybe you're right that it's not what we would do, but how can you, I, or any human possibly know whether it's what an alien species would do?
It's a nice fantasy to think you can zip back to the home planet after prancing around the galaxy making discoveries and reporting consequential and timely information back home.
Second, you have a very anthropomorphic perspective built in to your thinking. What if they had lifespans measured in centuries or longer? What if they had radically different views of life and death and generational cooperation? Alien life is, by definition, alien. It’s hard to say what would/wouldn’t be true.
What? How is it possible to trade intercontinentally without there being a colony to trade with first? that makes no sense. One does not go to a deserted island to do trade, with whom, the birds?
If anything, this is the commenter that is being more careful not to entertain familiar science fiction presumptions and is exhibiting the discipline that you're asking for.
> If anything, this is the commenter that is being more careful not to entertain familiar science fiction presumptions and is exhibiting the discipline that you're asking for.
I really don't understand why you think this.
(Good thing ʻOumuamua missed. Better luck next time, chumps!)
Our current model of physics is barely a few hundred years old. We’re talking about a civilization that’s potentially hundreds of thousands of years ahead of us.
Yes, there is a possibility we will learn more and there are other pathways, but at the moment, that is fantasy, so it would all be speculative.
It also assumes similar moral and cognitive processes of what to do when encountering another planet's life, neither of which must hold true for a society or species to become spacefaring. Likewise, an alien's AI probe could be effectively immortal and that would drastically shape its opinions on a return trip.
Or maybe they're intergalactic mayflies with innate knowledge for reaching orbit or relativistic speeds but they die each day and a new generation takes over tomorrow. All distances are suicide missions, even trips across their own planet. It would totally normalize multigenerational trips.
I think it's short sighted to make any assumptions of human similarities when it comes to first contact. Cephalopods have independently developed significant intelligence in parallel here on Earth and they might as well be aliens to us despite a common evolutionary ancestor way back. A completely independent evolutionary path leading to intelligence could be incredibly counter to our expectations.
Speaking of cephalopods, do they seem less aggressive than other species? Have they gone vegan?
Is it more or less likely the species that goes vegan wins the race? And even if they did it would mean that they had to subdue a more aggressive species. In other words, pacifists cannot unilaterally (en)force peace.
For the traveler's frame of reference interstellar travel with current technology is within reach of single human lifespans if you're fine with a one way trip (and extreme cost without an expected payoff). If a species lucked out with some right-sized planets and orbital arrangements they could end up with a great gravity slingshot by happenstance that drastically reduces their energy needs in space.
The awareness of the tyranny of the rocket equation again assumes human sized likeness of aliens. If human-like intelligence arises in ping-pong ball sized beings on a low gravity planet they could have a much easier time than we do escaping their planet and physics would be on their side for extreme-G launches that would otherwise be fatal to us.
So much discussion about aliens is hinged on them just being a copy of us but located somewhere else. It doesn't take a ton of imagination to envision plausible and entirely different starting scenarios that enable greater success in space travel without inventing new physics or exotic engineering.
Invasion does not mean prejudiced extermination. If they ignored us as we might ignore insects when we discover new habitat then, yeah, I’d want to keep them from coming.
Interesting times ahead
Solar isn't less steam and less engine, it's literally just solar, whereas everything else but geothermal and nuclear is solar with more steps. Natural gas and oil is just solar stored in paleo compost.
I need to go hug my wife and children
I guess, if a species used a Dyson sphere for so long, they will certainly have colonized other solar systems, which each have their own star to milk.
Large scale HUGE capacity electricity storage is a LOT further away than a lot of people and interests are willing to... well.. as we see in europe.. allow for. We are going ahead with the first half of a system that isn't even complete in theory.
The biggest open question with grid storage is which of the many competing technologies will come out on top.
Edit : solar don’t involve having a Dynamo spinning.
Since I can't imagine any easy way to have produced that as a typo, you may like to know that the spelling is actually 'rhetorical' (no accent in English, despite 'rhétorique' in French).
It’s a « us » phone born and raise in the US. But I fed him so much French that he is unsure about things.
I let it happen. Accent are fun.
https://solarsystem.nasa.gov/missions/cassini/radioisotope-t...
You can also do hobby-level usage like charging a cell phone with a candle.
1. What's the most efficient way to boil water?
2. How do we generate electricity on a population scale without having to boil water?
Question 1 is, apparently, much more tractable. We are still pretty much building the world's most sophisticated tea kettle.
Doesn't need to be the most efficient. Just more efficient per energy transferred to the water than all the other options.
Most efficient conpared to what we have already, but there may still be more efficient ways
https://en.wikipedia.org/wiki/Aneutronic_fusion
Helion Energy is the best known.
https://en.wikipedia.org/wiki/Helion_Energy
HB11 is another one
The others will just spend investors' money until it dries up. Helion too, most likely.
If you want to maximize pointlessness, Energy Vault is right there. But defrauding investors doesn't seem like a great choice to enable.
Maybe it would be better to do what might help avert global civilization collapse, thermonuclear war, and mass starvation?
Investing in practical energy-storage tech factory build-out, solar farms co-sited on reservoirs and pastures, cost-effective hydrogen and ammonia synthesis tech are all overwhelmingly better uses, and can all be equally as cool.
https://en.wikipedia.org/wiki/Tritium#Production
There's a lot of lithium being mined for batteries. Just centrifuge out Li-6 or isolate it with some other clever means. Not much is needed for fusion fuel compared to industrial scale consumers of lithium and it's a healthy boost to heat output.
Extracting tritium from a thousand tons of radioactivated lithium hydroxide at PPB concentration is left as an exercise for the ambitious reader.
Good luck.
Other neutron absorbers are contemplated, but extracting tritium from them on PPB concentration is no easier.
Designing the first wall and the volumetric blanket are, indeed, engineering challenges.
They usually can't adequately explain why in a single forum comment.
This topic is not one I'm personally familiar with, so possibly making an ass of myself, but (shrug).
It's a way harder engineering problem than you're letting on. Your comment is like a software user saying "How hard could it be just to add feature X?".
So it is all castles in the sky.
This problem has been known for decades.
http://orcutt.net/weblog/wp-content/uploads/2015/08/The-Trou...
https://pure.mpg.de/rest/items/item_2131865_1/component/file... (see section 4.1.1)
Boiling water using the Rankine cycle [2] and it will be as dead in the water as nuclear and coal is today.
A thing to keep in mind though is that it is very hard to compete with the engineering of an axle straight into a generator like wind turbines or a solid state system like solar PV. Working fluids, cooling loops and what not are awful to build and maintain.
In most western countries we can afford to transition to other solutions, and it is far healthier for both the people around it and the environment, but I don’t think most of the people on this site really understand the ramifications of not having cheap reliable power. There’s a reason people left the farms and flocked to dirty hellish cities during the industrial revolution and still flock to cities and build coal plants today. It’s less hellish than living without reliable modern amenities.
Southern California and the Midwest aren’t going to become uninhabitable even if we continue pumping out as much CO2 as we are currently. I know of no reasonable projections that predict anywhere near the human cost of just shutting off power completely if it’s not clean like people seem to want to do.
That does NOT mean we can’t reduce CO2 emissions while meeting increasing energy demands. But we should be striving to do both. And given a choice between living next to a coal plant and having reliable lighting, heating, air conditioning and food refrigeration or living next to a clean but unaffordable and unreliable plant, most people would choose the coal plant. We’ve been running that experiment globally since the industrial revolution, the answer is clear. Even when taking the health effects and climate change projections into account, that choice would be reasonable. Dying of cold, dying of disease due to unrefrigerated food, dying due to inability to call for help… these are all things very distant from the minds of most people fortunate enough to be on this site. They are very real ramifications of not having reliable power. And those severe ones I just mentioned are just the tip of the iceberg.
Lets just please, please, please finish the new stuff before turning the old stuff off. Build as many solar farms and wind turbines and nuclear and hydro and battery parks and hydro batteries and natural gas lines as we need, and only turn the old stuff off when we’re actually ready. If we turn off everything not clean preemptively we’re going to kill way more people than climate change. If we were reasonable and sought to actually solve emissions problems as fast as possible there is no reason not to aggressively pursue wind AND solar AND hydro AND nuclear fission AND natural gas.
It’s sad I can make this prediction about your opinion, but I’m assuming you are probably not an advocate of fracking or nuclear power or hydro. Please correct me if I’m wrong. A lot of people apocalyptic about climate change are quite picky and refuse to pursue solutions that don’t conform to a perfect vision of a star trek like future where everything looks like the apple campus. It’s delusional.
It speaks to the privilege of those advocating green energy “at all costs” (which is not actually at all costs and maximally translates to “at the cost of the poor” due to the aforementioned pickiness) and reflects a severe lack of appreciation for the ramifications of less reliable and more expensive power on the poor.
The fact that most people on this site are surrounded by opulence and excess is creating a severe disconnect with the reality of the wider world. That default reality is that the only reason the climate isn’t killing way more people in the here and now is cheap power.
If you want to talk about "redeeming" then you need to include externalities, and those are pretty bad for coal.
> the human cost of just shutting off power completely if it’s not clean like people seem to want to do.
Nobody wants to do that, stop being weird.
It did strike me as a pretty egregious straw man. I don't think I've ever heard anybody argue for just turning off coal plants and sitting in darkness, certainly not the poster being replied to.
In the last 20 years, the percentage of US energy coming from coal has fallen in half. Eliminating is entirely achievable.
From what I understand it seems reasonable to get rid of coal in the US over a reasonable time frame with appropriate replacements. I’m not arguing in favor of coal. I’m arguing in favor of going with cheap reliable energy and whatever the best and actually practical solutions are for a given area.
The fact that coal has fallen by half in 20 years doesn’t mean the other half is just as easy, either. You need a certain amount of supplemental power at night, during bad weather, during usage spikes, etc. The remaining percentage of coal use is going to be more and more concentrated in the supply areas that are harder to replace. That doesn’t mean it can’t all be replaced or that we shouldn’t pursue replacing all of it, all I’m advocating is for a sane transition that takes practical constraints like that into account and doesn’t get perfectionistic about solutions. Frankly I don’t often see considerations like that being made, I see a lot of hysterics and dogmatic assertions about how everything needs to be solar panels and wind turbines yesterday and everyone who wants moderation or other green solutions and more gradual phase in is a greedy oil shill.
Then you're not doing a very good job of it. For all that you accuse others of "hysterics and dogmatic assertions", I think your posts earn that label way more than the comments you replied to.
Worse according to who? Climate activists? Or people who are going to freeze to death because those “worse” options weren’t kept online?
Lol yeah you’re wrong. We’re on HN after all, everyone loves nuclear. Fracking is also horrible for the environment and for climate change. Most wells leak methane which is a 6x worse greenhouse gas than CO2. Hydro and nuclear are fantastic, although we’ve dammed most places we can in the US already. Anyway I’m against coal, the climate is a cost of coal, it isn’t cheap for society. I’m for investing in doubling the nuclear capacity of this country to eliminate coal completely. Or spend the trillion dollars we’ve dumped on wars to build a superconducting power grid and save the transmission waste. Also as others have said your argument is a ridiculous straw man. Nobody is talking about going back to the Stone Age. Just talking about how to build cleaner sources of energy. If the weather of the past year hasn’t convinced you of the necessity of this, I’m afraid for the future of the world.
That argument is not a straw man. I know very few want to go back to the stone age (some radicals do), that’s not my argument. A lot of people vastly overestimate the ease of transitioning and are making laws and goals and plans that are wildly optimistic and out of touch that will in effect lead to unstable grids and more people without power. No one sane wants that, but that’s already happening because a lot of places that have been aggressive about transitioning have done it poorly and without proper backup power generation options.
If COVID hasn’t convinced you rushed and panicked centralized interventions make things worse, and you’re willing to engage in even more of the kind of massive disruptions that we’ve only begun to see the full effects of because of a heatwave, you’re likely to kill more people with rushed intervention: https://nypost.com/2017/07/10/heat-death-hysteria-the-wrong-...
I meet a lot of people that are dogmatic about wind and solar and think it’ll work by itself and that the whole world needs to transition to that alone right now. In combination with other sources, in the US and rich countries we can afford to build all the clean energy we need, if all options are actually on the table. But doing that globally and doing it too fast will kill people.
Thank you.
The syllogism works the other way too.
We don't have the luxury to wait on nuclear either. A large part of the current French electricity crisis is "thanks" to the cost and time budget overruns of Flamanville - they had gambled on Flamanville being ready in time to replace the old unreliable clunkers that, surprising nobody, now have massive corrosion issues.
The solution is to massively over-build on renewables - wind and solar most obviously as well as trans-continental ultra-high-voltage links, but also biogas plants that convert the millions of tons of cow dung and other bio waste into gas that can then be used during low availability of renewable electricity. On the other side we also desperately need actually smart grids and consumers that can dynamically act based on the power available in the grid.
Also Texas, another state where they pushed green energy (wind) and slowed the investment in fossil fuels.
We all want cleaner energy, but we must acknowledge that it is not easy.
On the contrary, Germany has met their goal of 80% full natgas storage several weeks early despite the French nuclear reactors being offline due to higher than expected renewable energy supplies.
They invested a lot in solar power, which is expensive, so they couldn't afford to invest enough in transmission and backup generators, and now they have expensive electricity and unreliable grids. Ignoring current year, I think Germany is second in the world in regards to expensive electricity (after Denmark) and California is one of the most expensive states in the US.
Of course they have not finished building out, which takes time. And, Germany counted on access to NG as backup while they build out. The war interfered. Had they invested any other way they would be even worse off.
This is an outright lie, let me dig in a bit. They're cheap only if you look at watts generated, if you ignore extra grid costs and backup supply. For 1 MW of solar, you need 1 MW of backup. If you use solar for most of the day and use the backup just for 20% of the total electricity required, then the backup plant will look like it's very expensive to build and operate, while the solar seems cheap. But solar cannot operate without backup.
What needs to happen is that you have to transfer some of the money generated by the solar plant to the backup plant. How you do that will make it look like solar is either very cheap, or expensive - and this is all political and a PR move. In the end, consumer will pay for both anyway, which is why Germany and California have such high electricity bills.
A real life equivalent example would be to say that your truck can downhill with 100 MPG and very cheap to run, and this is absolutely true...if you ignore that the truck must also climb the hill.
> Had they invested any other way they would be even worse off Germany is lucky that EU just implemented the unified energy market, otherwise they would have been absolutely obliterated this past winter + wartime.
It's like buying a BMW and then not having enough money for groceries...it's not just the groceries being too expensive, the nice shiny car might have something to do with it.
That's why we are considering placing a converter above the sky to more efficiently pierce the sky with energy.
I hope we have a bright future growing into space, creating a Dyson ring, orbital habitats, etc.
Replacing our current use of fossil fuels has plenty of strong ground-alternatives. I like the idea of Thorium salt reactors for base load, hydro stored energy and lots of local wind and solar.
(for the uninitiated: https://youtu.be/3m5qxZm_JqM)
https://energyeducation.ca/encyclopedia/Solar_energy_to_the_... Demonstrates otherwise. About 30% is lost to the atmosphere, 70% reaches the surface.
The UK is building two of these pump uphill things. Four more and it could sustain a 99% carbon free grid on solar and wind alone.
So?
> Nobody has put forth a credible theoretical model on how to do it.
HVDC global grid, mentioned loads of times on this forum. 60% antipodal loss with existing components that were optimised for much shorter connections, but even that loss is fine given how cheap optimally placed PV is. Cost about a trillion USD (ok) and a few decades of current global aluminium and copper production (meh), but that’s still absolutely in the realm of the “we could afford it, shame about the politics”.
It is, in fact, not. And, you are no reliable judge of it. Your assessment will have exactly zero effect on how the transition to renewables plays out.
Either we transition to renewables fast enough, or global civilization collapses first. Nobody can say which.
https://ieeexplore.ieee.org/document/9837910
> Even former critics must admit that adding e-fuels through PtX makes 100% RE possible at costs similar to fossil fuels. These critics are still questioning whether 100% RE is the cheapest solution but no longer claim it would be unfeasible or prohibitively expensive.
Of course, this is actually desirable imho, but yes, both geopolitics as well as cost, stops this from happening.
So, storage is just a part of the grid, and the grid may be fed by wind, solar, hydro, and geo "alone".
strictly speaking, sure. But it's a source for all intents and purposes, because in order to achieve the same outcomes using renewables as with fossil fuel powerplants, you'd need to pair it with storage. Or produce so much renewables, and be able to distribute it so widely, that no single location would lack power at any given time.
The fact remains that the physics of a grid powered only by distributed non-dispatchable wind and solar resources simply does.not.work. full stop without massive investments in storage and transmission upgrades. The physics isn't even debatable - it's simple. You only have to look at the very limited transmission infrastructure that currently exists and understand the simple fact that the power grid is a zero sum game. Power in = Power out or very bad things happen that lead to power out = 0. Zero sum generation + aging transmission = not enough power where you need it, when you need it if you get rid of traditional baseload sources.
It's good to champion renewable generation, storage, and transmission upgrades. It's necessary infrastructure for the economic and actual health of our nation. It is not going to be inexpensive by any definition of the term. It's going to be monumentally expensive even if it's completely necessary.
a) Once it's done, you're pretty much self sufficient energy wise. Sure, you may need the raw materials from other countries to make panels, turbines and batteries. But once you've achieved a 100% renewable clean energy grid, you're getting a fairly decent lifespan out of everything so you're not going to be as subjected to the whims of the market like most of Europe is experiencing with gas. The market should generally be more stable.
b) Once your citizens have free energy, they have a massive chunk of disposable cash they were once spending energy. They will spend that or invest it: and both general spending and investing are taxed at higher rates than fuel spending (5% VAT on fuel spending in UK compared to 20% general VAT rate). Yes that is a massive loan for the government to put on the books, but they will probably get it back much quicker than expected.
What arm of the USA government do you trust most to get this job done efficiently and fairly? What do you think will happen when you use "more than your share" of electricity for a month or two and your (undoubtedly centrally controlled) account is deemed unacceptable? Or is it your thought that providing electricity free will reduce consumption?
As for the second part, privately owned houses would get as much energy as the solar panels and battery on their property can provide. Additional power would come from the grid and would have to be paid for as normal. For people in apartments, presumably you have records of normal energy usage for every house and apartment, you could use those to work out the amount of solar panels needed to add to a solar farm or the equivalent for wind. The government pays for the installation of that and the citizen gets the energy generated for free. Additional energy they use is then paid for out of their own pocket.
Once we have built the machinery to harness that energy, it does become pretty much free and we can use as much or as little of it as we like. The cost of maintaining the machinery will become ever cheaper due to the amount of power we can get for little to no effort. It becomes self sustaining.
There are literally ongoing efforts right now to replicate Asimov’s vision which was to create space based solar farms and transmitting the energy back down in radio waves to specific points. We could literally harness our entire planets energy use from just a few of these in strategic locations if it was done right:
https://www.getsunsights.com/will-the-concept-of-space-solar...
It turns out your ability to harness energy is kind of important. We're nowhere near that level of energy capture. We can't even handle transmitting solar from one corner of one smallish continent to the other, we're nowhere near the level of technology and infrastructure development you're talking about.
If you give people an unlimited amount of free power they're going to use it to mine cryptocurrency in a massively wasteful and expensive way.
So, we build storage and transmission. Storage cost is falling even faster than generation, and there are zero physics problems to be solved, just practical civil engineering.
The cost of this much civil engineering will be very large, but much smaller than e.g. for that much nukes, and we will pay it, because the only other choice is global collapse when the degraded biosphere becomes unable to sustain our population.
> Storage cost is falling even faster than generation,
> and there are zero physics problems to be solved,
> just practical civil engineering.
[1] https://cleanenergynews.ihsmarkit.com/research-analysis/grid...
> Alchemy is not a solved problem
Ah, trolling. OK.
What form of grid/utility energy storage do you expect will dominate in 20 years?
I provided a reference to back up my assertion. Do you have any?
Everything comes down as manufacturing volume goes up.
I'm seriously hoping that aluminium-chalcogen batteries [https://www.nature.com/articles/s41586-022-04983-9] can be scaled and commercialized soon
Other exciting chemistries include molten antimony/calcium, zinc/bromine, and iron/air. The antimony/calcium one would never wear out or catch fire. Zinc/bromine is most compatible with current lead/acid battery tech. Iron/air is very, very cheap. None are very attractive for cars, so utilities will not be in competition with the car industry for access to batteries.
We can make it -- in a fusion reactor :)
Oh is that all. How could nobody have thought of this yet?!?!
Remember they were replying to a claim that it would be "inexpensive"
At issue is how this cost compares to that. Renewables and storage costs, as big as they will be, will be overwhelmingly less than alternatives, and can be fielded faster.
https://ieeexplore.ieee.org/document/9837910
> Even former critics must admit that adding e-fuels through PtX makes 100% RE possible at costs similar to fossil fuels. These critics are still questioning whether 100% RE is the cheapest solution but no longer claim it would be unfeasible or prohibitively expensive.
Anyway, I now expect you will apply the same level of skeptical criticism to anyone stating renewables are insufficient, and demand they supply peer-reviewed references.
Seriously though. Maybe, if we solve the large capacity storage issues and are able to build a storage system to scale. So 3 or 4 decades if we are extremely lucky. But right now in reality....
And it's still not clear if it would be enough in the end. We'd need cover everything in panels and put towers everywhere. The amount of resources needed for solar and wind is actually realistically insane at the scales needed. (one of the many problems usually ignored by wind/solar evangelism)
https://www.nrel.gov/docs/fy04osti/35097.pdf
"In the United States, cities and residences cover about 140 million acres of land. We could supply every kilowatt-hour of our nation’s current electricity requirements simply by applying PV to 7% of this area—on roofs, on parking lots, along highway walls, on the sides of buildings, and in other dual-use scenarios."
"We would need only 10 million acres of land—or only 0.4% of the area of the United States—to supply all of our nation’s electricity using PV."
And renewables happily coexist with other uses of the same land, so none is used up.
That doesn't mean it's made clear in statistics. I've read plenty of people say "X generates as much as Y", where X is intermittent and Y is suitable for base load. Certainly enough to disagree that everyone knows it and is able to discern that from context-free statistics.
I'm not saying if people think it through they won't understand it, I'm saying that context-free stats like that create false impressions in some people's minds based on whatever the assume about the stat, and annoy people like me who'd like to know where the stat came from.
That’s 10 million acres of wires, maintenance, habitat and all kinds of mischievous creatures, not least of which are humans. And it only works when the weather is good. And not all countries have the grid or engineering and maintenance capacity of the United States.
It’s not a realistic solution.
By all means, lets put solar panels everywhere we already have buildings and roofs and power hookups and make a dent. Maybe at some point it’ll be possible to use solar alone, and we can keep up the maintenance.
Going all in on solar right now would be suicide. It’d be worse than the effects of anthropogenic warming. People are going to freeze to death this winter in Germany because they bought into the promise of renewables before it delivered and didn’t diversify their energy supply.
You should only phase something out when you can meet demands without it. Nuclear is a way to do that. Natural gas is a way to do that. Renewables are a way to do that. But you have to actually exceed demand and have a solid diversified base before you panic switch because of climate change. Otherwise you kill and impoverish more people than climate change.
Agriculture is already working, or was until its been starting to be shut down and curtailed due to alleged environmental issues like in the Netherlands. You can manage much larger chunks of land with plows and combines and other vehicles because of how you interact with the land when farming.
You can’t plant solar panels and have them just grow out of the ground and repair themselves and reproduce largely independently. It’s a totally different type of land use. Managing solar farms is magnitudes more effort to build and maintain than agriculture.
They require less money to build, and less to operate, than nuclear (per unit of energy output).
So, your talking about land could only be a valid objection if land itself was the constraint. And that's what my snark about eating was aimed at.
This claim that 10 million acres of solar panels is cheaper to build and maintain and actually put into use and store power from vs extremely high energy output nuclear plants with tiny footprints that can produce continuously reeks of extremely biased accounting.
That does not mean you’re wrong, I simply don’t trust your hand wavy dismissive argument about it being cheaper.
If I see a report that looks at the long term maintenance cost of an actually deployed modern solar farm, not hypothetical ones, and compares it to an actually deployed modern nuclear reactor, I’ll take that one.
I have an affinity for whatever actually works, the main reason I think nuclear looks good is I trust basic physics and understand how much astronomically higher the energy density of nuclear power is in comparison to like everything else.
A renewable grid includes storage. Storage is cheap and getting cheaper.
In fact, it's long been addressed, and the cost of dealing with intermittency of renewable sources appears acceptable.
https://ieeexplore.ieee.org/document/9837910
> Even former critics must admit that adding e-fuels through PtX makes 100% RE possible at costs similar to fossil fuels. These critics are still questioning whether 100% RE is the cheapest solution but no longer claim it would be unfeasible or prohibitively expensive.
As explained elsewhere, a mix of energy sources is necessary.
And your statement is devoid of context. Solar is already working well in North America (and elsewhere), and uptake will continue to increase. It won't be a panacea for the rest of the world, and solar+wind won't replace all other generation types.
Not sure why you're dismissing it so out of hand. I agree it's not the panacea that many want it to be, but it's still very important, especially given its recent cost declines (solar specifically here).
Actually thinking about it figuring that out would make fission a lot more tenable too
But we already know that fission, too, is uncompetitive, moreso each day as costs for renewables and storage continue relentlessly downward.
Fusion has no chance of ever catching up.
i.e. one needs to prevent the neutrons from escaping or degrading the material the reactor is made out of, so instead of just adding a throwaway shielding layer, would it work to use something that is not only super dense, but is currently a waste product[1], and also becomes more valuable in the process of being used as the shield? Seems like it would be vaguely equivalent to a photoelectric collector for neutrons, but I am not a physicist or reactor engineer.
[1] I do think it's a shame that we stopped building breeder reactors, but that's a separate discussion.
The overarching requirement on fusion neutron absorption material, besides delivery of heat to process steam, is that it needs to produce more tritium to burn. You don't get that if the neutrons are absorbed in something other than lithium.
Though you'd need something very different from existing photovoltaics to capture the energy from those x-rays.
It will never produce so much as one kWh of commercial power.
These photons can’t usefully be converted directly into electricity with the photoelectric effect, but they sure could be converted indirectly via the same mechanism that the fusion in the core of the sun is reduced to the band that current PV runs at.
Not sure if it’s worth doing that (may well be such a diffuser would be so large it would be easier to do something completely different), but that’s very different thing to your dismissal.
Cooling? an IR barrier in the reactor to stop IR from reaching the cells should solve about 80% of the issue - assuming you can make something transparent at the right wavelengths for the cells - and capable of withstanding the heat of the reactor. The other 20% is already doable with current technology, and we do it from large-scale solar farms to single-family homes - water tubing on the backs of the devices to a radiator or storage tank. Hell, while using them to harvest light energy, that water loop can be used to harvest heat energy, thus improving the overall system efficiency!
If that's 600 MWe, running at 80% capacity factor, amortized over 30 years, then the $2B becomes: 2e9/(600 * 1000 * 0.8 * 24 * 365 * 30) = $0.0158 / kWh -- the $2B capital cost amortizes to 1.6 cents per kWh of electricity sold. Not zero, but 1.6 cents is far less than the current market price of a kWh.
If you're going to compare to utility-scale solar or wind, be sure to include their much lower capacity factor: https://en.wikipedia.org/wiki/Capacity_factor#/media/File:US...
(Admittedly: we don't yet know the capital cost of a working fusion heat source, or its capacity factor. Both will determine whether this is economically competitive.)
On page 15 note "This analysis does not take into account potential social and environmental externalities or reliability-related considerations", and that solar and wind do not get the checkmark for "baseload" -- only "intermittent".
Pages 13 and 14 show Fuel Costs as:
Wind: 0
Solar: 0
Coal: $13-$18/MWh ($0.013 - $0.018 per kWh)
Fission: $9/MWh ($0.009 per kWh)
Natural Gas: $21-34/MWh ($0.021 - $0.034 per kWh)
Fusion has the potential to be very low on fuel costs. But the capital costs are an unknown. In my original comment, I tried to show that when amortized over enough kWh for sale, even $Billions in capital costs could make sense, if they give us a machine that produces zero-carbon baseload electrical generation at scale.
Fusion plasma must be sustained at a few million Kelvin or it shuts down again, and I'm not sure how finely we can control the operating temperature without either overheating the reactor or shutting down the plasma. I think it will take a lot more than dumb engineering to accomplish this.
Then I pointed out that our electric car does it in both directions too.
electric <-> kinetic - spinning magnets
kinetic <-> pressure - turbine / pump
pressure <- heat - boiler
heat <- chemical potential - furnace
I'm being silly, but I'm genuinely curious if there are any plans, even speculative ones, on how to do this.
By the time this could be made to work, nobody will want it at any price.
Also, when dealing with that much high energy radiation, your metal has a tendency to wondrously become another metal, with all the problems that comes with.
we want a lot of water! That's a lot of energy!
> Also, when dealing with that much high energy radiation, your metal has a tendency to wondrously become another metal, with all the problems that comes with.
That's kinda problem with anything fusion or fission, wherever neutrons hit things get weird. Probably much worse for fusion tho.
I believe the containers would have to be really large.
Also, if we have to continue boiling water at scale, we might reach water crisis some day. Although, it'd take very long time.