A near 100pct renewable grid for Australia is feasible and affordable | Hacker News Reader

A near 100pct renewable grid for Australia is feasible and affordable

reneweconomy.com.au

65 pointshackerlight116 comments

I worked as a quant in energy for the Australian market.

I did the same thing as OP but didn't assume electricity teleported 3,000 km from Tasmania to Northern Queensland.

Using the proprietary data for what each pole could carry I build a first principles simulation of the Australian grid to find where medium sized battery installations should be placed to provide maximum grid frequency correction.

The grid is already close to collapse on 40C days.

Forget moving to a renewable grid, keeping the lights on during a five day heat wave over the eastern seaboard is currently impossible.

Pardon my ignorance, but isn't aircon an easy case for the grid? The same sun that causes the heat can power solar panels, so it doesn't even need storage or long-range transmission.

You are assuming that you don't need an aircon at night. Something that's very much not the case during a multiday Australian heatwave.

Do you have any insulation? I'm in the UK, and my previous rental had walls that leaked any heat within half an hour, but my current one, it heats up to 23 in the day due to the large windows facing the sun, and barely drops to 18 at night when it's 5-10 degrees outside.

>Do you have any insulation?

No, this is Australia. Houses are more like tents than actual buildings.

Tents are sturdier.

> No, this is Australia. Houses are more like tents than actual buildings.

Pre-AC being ubiquitous (or being invented), the way for people to cool off in summer was to have airflow. Insulation was a more of a cold climate thing, as keeping the heat in / cold out was more intuitive when burning wood or coal: thermal boundaries were more 'needed' when there was snow outside.

Having thermal boundaries in your structure didn't make sense when it was as hot inside (due to lack of AC) as it was outside, and it has only been in recent years that people clued into that fact. But unfortunately there's a large stock of housing around that was built pre-clue in.

Even now there are people who insist that houses need to "breathe", i.e., have holes / be drafty. They do not:

* https://www.energyvanguard.com/blog/Myth-A-House-Needs-to-Br...

* https://www.greenbuildingadvisor.com/article/most-houses-tha...

* https://www.greenbuildingadvisor.com/article/buildings-dont-...

Buildings need to be as air tight as possible, and be ventilated through mechanical means so that stale air is vented out and fresh air is brought in after being filtered and tempered (via an ERV).

>> Buildings need to be as air tight as possible

Perhaps in California, Australia or other desert areas. The pacific northwest had major issues when OSB met the concept of "air tight" housing. No airflow in/through walls leads to condensation, mold and collapse of many "engineered" wood products held together with glue.

> The pacific northwest had major issues when OSB met the concept of "air tight" housing. No airflow in/through walls leads to condensation, mold and collapse of many "engineered" wood products held together with glue.

These are not indicators that air tightness is bad, but rather that people don't understand building science. Washington state (for one) has mandated air tightness levels (§R402.4.1.3) and testing (§R402.4.1.2):

* https://sbcc.wa.gov/sites/default/files/2023-04/2021_WSEC_R_...

Air tight passive houses are built without issues in the US PNW:

* https://phnw.org

* https://hammerandhand.com/high-performance/passive-house-bui...

* https://asiri-designs.com/f/how-to-design-an-energy-efficien...

The province of BC is mandating near-passive house levels of air tightness:

* https://www.energyadvisor.pro/airtight-energy-advisor-contac...

* https://energystepcode.ca/how-it-works/

* PDF: https://www.bchousing.org/publications/Illustrated-Guide-Ach...

Build your structure according to how physics works and it will work just as well from the tropics (IECC Zone 1) to the arctic (IECC Zone 8):

* https://buildingscience.com/documents/insights/bsi-001-the-p...

* https://basc.pnnl.gov/images/iecc-climate-zone-map

Air tightness is coming to building codes everywhere, and if you can't make it work then you shouldn't be building because you are incompetent:

* https://www.iccsafe.org/building-safety-journal/bsj-technica...

You massively overestimate how deserted Australia is. Most of the population of Australia lives in the greener areas near the coast, which has a much more moderate climate.

...also I doubt anyone from e.g. Brisbane would need to be told about mold and condensation.

> Pre-AC being ubiquitous (or being invented), the way for people to cool off in summer was to have airflow.

Modern A/C was invented in 1901, and A/C penetration in Australia is not that far behind the US.

But much as in Texas where houses are also made of paper and cardboard, cheap energy has made forcing temps down via AC much simpler (for property developers).

I have a "normal" Melbourne brick veneer home, with decent roof insulation and insulated curtains. It handles the heat well for 1 day but a 2 or 3 day heatwave of 38 degree plus temperatures the bricks heat up in the sun and it gets quite uncomfortable even at night.

outside sun shield like German houses have is the way to go. Any curtains inside does not work very well

Spent some time in Oz in the 90s- trying to sleep at night in my 2nd floor apartment as the heat rolling off the desert met the Brisbane coast without air conditioning remains some of my most unpleasant memories to this day.

Despite a fan pointed right at me I’d awake every morning with a sweat soaked mattresses…

Brisbane is quite pleasant compared to the NQ. Good times.

Source: In brisbane and lived in the north.

Yep, visited Townsville and it was even more hot/humid, I imagine places like Cairns take it up even further but don’t have quite as much hot desert air sweeping in as Brisbane since its more of a peninsula.

How did people in Australia get by before air conditioning?

I'm not saying that to be snarky, I would generally love to know. I live in a moderately cold climate (England) and I often wonder how people here survived through the winter before the comforts of modern technology. And England's not that cold - how the hell did indigenous Canadians do it, for example? Did people just shiver by a fire for months at a time?

EDIT: I didn't think I was being snarky in my original final sentence, but to avoid misunderstandings I've removed it.

The first sentence is a good question, the last sentence is unnecessary snark.

I think there are two main things at play: buildings used to be built differently, and yes, people prefer not to suffer these days.

Old Australian buildings (e.g. "Queenslanders") were often built on poles to let the air circulate underneath, they'd have the roof extend far over windows to stop sunlight (and heat) getting in. Those are not the most enjoyable places to live in, these days people prefer a bit of sunlight during the day, and a constant draft is not pleasant in winter.

And yes, I imagine people just didn't sleep all that well and spent heatwaves sitting around in the coldest spot in the house waiting for it to be over. These days people want to sleep well throughout the year and want to be productive even during heatwaves.

People were also a lot harder back then because life was harder through the entirety of their existence. Obesity was rare, the average level of fitness was much, much higher, and the teens and adults probably showed a bunch of survivorship bias for hardiness because the weakest died during childhood pretty routinely. I suspect environmental conditions that would kill the average diabetic, obese 45 year old today was just a normal summer day to people back then and was well mostly well tolerated.

I live in Minnesota and have spent a reasonable amount of time winter camping. You use these cool canvas tents and a small, packable wood stove. This has brought me into contact with some folks that live lifestyles somewhat closer to those old days than the new ones - so far as expectations on infrastructure go. For one, they wear warm clothing almost all the time. It’s significantly more efficient to heat yourself (through clothing, food and movement) than heating an entire room/building.

Also: wood stoves large and small can pump out a lot of heat. You can kick up the small tin metal camping stove and make your canvas tent 75 degrees, dry out any wet clothes. Likewise, a large iron stove can make a room boiling. After all, saunas - in one form or another - are a common feature of northern cultures.

Fans and light clothes, mostly.

A lot more people live out in cheaply built homes with small, barren yards and dark roofs that are literally designed for air conditioning. Older homes often have better airflow.

An example of a newer suburb in Sydney is Marsden Park: https://www.youtube.com/watch?v=WzV3H_K73To

I don't use/have aircon in my home in Brisbane and I get by fine :) Although it is nice to have aircon in the summer when I'm working on the computer and need to concentrate (my office at work is air conditioned, like most).

Go to the rural Philippines and you'll find plenty of homes without air conditioning in 40+ heat.

You'll also find westerners accustomed to air-conditioning who live there and have "adjusted".

It takes about 2 weeks and your body makes some sort of adjustment.

It's an interesting phenomenon that maybe someone here can comment on more fully. By that I mean what exactly is happening to us when we adjust? Is it purely psychological or are there actual biological changes/effects at play? Whatever it is you really do "adjust" and it's not that bad after a few weeks. You even learn to sleep well at night in sweltering heat...again after you adjust.

Of course there are limits but we're built to handle the heat.

Heat comes from the sun, but in reality after the sun. Generally speaking, the hottest time of the day (late afternoon) isn't when the sun is brightest (noon). Then people need to sleep, which means they want to be cooler during the evening.

One way to beat the heat is to adjust the workday. Start work at noon. Let people sleep during the cool of morning. But that is a bridge too far for most cultures.

Start at noon? That’s the exact opposite of the approach people take when it’s hot around here (I live in southern Australia where it regularly breaks 40C in summer). Start early - before the sun’s up if you can - and be ready to knock off soon after lunch.

Where I live (French Alps) that's true, because there is a big circadian delta, meaning I can have 30+℃ (86℉) during the day, but at 7pm the temperature is already 25℃ (77℉), at 9pm 20℃ (68℉), at midnight 17℃ (63℉) etc.

But where I was born (northern Italy) the circadian delta is MUCH lower, if it's 35℃ during the day, the night minima is 30℃ at miminum. So you need aircon 24/7, not just during the day.

Do you have 40C cloudy days? If not, you don't need to teleport electricity to handle sunny days, you just have to build more local solar generation.

This is what the sky looked like the last time there were more than three days over 40C in a row in Melbourne: https://i.insider.com/5dfc7162e94e8636622f1667

It is also somewhat difficult to use solar power for cooling at midnight when it's still 35C.

It's super easy. Cool to 20C during the day and close your windows. In the morning you should be well under 22C.

I can do the inverse: warm my house to 22C and turn off the furnace overnight when it's -30C. The house won't drop below 20C. And that's a 50C differential. A 14C differential is trivial in comparison.

So you have thousands of dollars worth of insulation because you live in an arctic climate.

Congratulations I suppose.

Now instead of just spending hundreds of billions on building a new grid Australians will also have to spend hundreds of billions on insulating their houses.

To be completely honest, they probably should, and people don't talk enough about proper insulation regardless of the region.

E.g. in colder climates many modern buildings are just hermetically sealed boxes with issues around CO2 levels etc.

For a 14C differential you don't need insulation, you just need to seal leaks.

> For a 14C differential you don't need insulation, you just need to seal leaks.

And hope that your inside air temperature is not at the dew point of the hot, humid air that is outside (thus causing condensation).

If your house had problems with condensation forming on the outside then I hope it never rains where you are.

Water in liquid form (e.g., rain) will (mostly!) go down with gravity, and so overhangs will help a lot, as will proper grade sloping away from your foundations.

Water in vapour form will be more diffuse and be everywhere the air is.

Further, your cladding / water control layer (which deals with rain (and UV)) generally needs to be open to air so that it can dry properly:

* https://en.wikipedia.org/wiki/Rainscreen

so that can lead to moist air getting places that water may not, and if you don't have insulation between the warm-moist outside and the cool-dry inside:

* https://buildingscience.com/documents/insights/bsi-001-the-p...

problems can start.

The picture in my mind was: You have overbuilt solar charging nearby batteries (lithium ion, sodium ion, whatever) to cover the 4-hour busy period at night, and smaller amounts of longer duration storage like pumped hydro to cover the quieter periods after 10pm.

I'm not sure if that'd work out to be cheaper than doing the proposed 60% wind/45% solar mix with inter-state transmission. It would reduce the need for new transmission lines, though.

Aka, really sunny just as suggested.

Cooling at night requires batteries, but their cost is offset by how cheap they are to charge with excess solar resulting in positive feedback loops.

Further, AC needs to work far less hard at night as you avoid solar gain through windows etc, fewer devices are on reducing heat gain, outside temperature drop further reducing heat gain while also increasing AC efficiency.

Or, to echo the main point of the OP: just use gas peakers for these rare events, and when climate deniers try to give you grief for not being 100% pure, wipe your tears with the millions of dollars you've saved by adopting cheap renewables for the other 97% of the time.

If you did the same thing as the OP then you'd have some numbers to share, rather than vague fearmongering about grid collapse.

That sounds really interesting. How did you go about creating such a simulation?

At moments like this it is important to remember that models are notoriously wrong. The take away for me is that we're getting to the threshold where solar is genuinely an economic option and if the price of solar energy keeps coming down it'll probably be the energy source of choice in Australia.

The article talking about 'replacing' is a bit weird, that doesn't make any intuitive sense. We'd keep the existing generation infrastructure then start augmenting it with cheap renewables.

Solar is stupidly cheap. I'm building a 40kw hybrid system with 50kwh of storage for less than 20k USD in Thailand. It's this cheap because there is 0% duty on my solar panels and inverters, I was able to source locally made aluminium racking. Of Course that is a DIY price, commercial installation would have been a lot more. However there was still 30% duty on the batteries that doesn't need to be there IMO.

Australia should negotiate a deal with China, remove all import tariffs on green energy products in exchange for guarantees of local manufacturing being setup here within 5 years and then subsidize the shit out of everyone doing rooftop solar with storage. If you remove the tariffs on LFP you can easily get down to $100USD/kwh for storage and similarly for panels $125USD/kw for rated power.

If everyone is running rooftop solar w/storage and not doing any export (or minimal export) the grid impact is purely positive and doesn't require smart grid shit to regulate things. It's possible to add an absolutely massive amount of capacity this way cheaply, without tech or solutions that don't exist yet and without much political capital being burnt other an upsetting some butthurt Americans that you are doing business with China.

What's the net metering situation in Thailand. I assume not that good if you decided to get storage. Did you get a lifepo4 battery?

There is net metering but it has two major problems.

1) It's hard to get approved, doubly hard for a DIY installed system, even if I could jump through the hoops (eletrical engineers drawing etc) there is also a quota so there isn't a gaurantee it would be approved.

2) The rate isn't that great, it's about 30% of retail.

However all of that is moot in my case because my power needs exceed that of the available utility power at my location.

So I essentially have a 3 phase completely off grid solar system. So why did I say hybrid? Well that is because I do have a utility supply but it's a 15/45A supply but it's got horrible voltage drop (I'm 2.5km up a mountain from the transformer) and it's 1ph and I need 3ph power for my EV charger, air conditioning and pool pumps.

So what I did was add an AC charger that is configured to charge from grid if the batteries drop below 30% state of charge. So it's essentially a hybrid system, DC coupled to the 48V batteries but really the grid supply is just a backup, the system is specced to operate completely off-grid.

Yes the battery system is LFP, I went for 5 x 48V 200AH server rack mounted packs in parallel.

I'll probably also eventually add a diesel generator so that there is no way I will ever lose power but for now the batteries + grid charger are going to be enough.

The grid was much nearer to collapse seven years ago when there were actually brownouts, and renewables have been entirely responsible for its improvement. Moving toward renewables and keeping the lights on in Australia are the same thing.

It's amazing to hear people arguing that the highest electricty prices in the OCED are somehow a sign of a working system: https://www.leadingedgeenergy.com.au/blog/highest-electricit...

Not only does the Australian market have the highest consumer prices it also has the highest number of negative pricing events.

In short: the only reason why the grid hasn't had a brownout since 2019 is because there hasn't been a major heatwave since 2019.

The article you linked is from 2017. 80% of Australia's solar was installed after that came out. Hard to argue that it's somehow responsible. Seems like your knowledge is a bit outdated.

I do wonder why there isn't far more solar in Australia already everywhere, given that it's a country of dry deserts and strong sun.

Australia is transitioning >3% of their electricity supply to solar per year and still accelerating. Rooftop solar is near 50% uptake. Combined with wind, they are on track to almost fully in the next 10 years. So there will be soon.

Half the population of Australia (marked in red): https://imgur.com/dA92oJp

Most of the dry desert is irrelevant.

If nobody lives there, it's a perfect place to put some panels.

Just saw this story that the Australian government is to kick-start a billion dollar program to develop the solar panel supply chain here. https://www.abc.net.au/news/2024-03-28/anthony-albanese-anno...

Feasible in a technical sense, but you have to unseat the coal industry representatives, which is going to be hard.

Or do a Norway and partially nationalise coal production for export while investing profits into renewable for domestic supply.

Why would the coal industry vote for that?

Sounds like something the coal industry would fight even harder

During Australia's mining boom in the early 2000's, the government was making tax dollars hand over fist. What they did was then offer all kinds of tax cuts that Australia couldn't really afford long term. Better explained here: https://www.smh.com.au/opinion/federal-budget-hangover-peter...

Basically, they purchased popularity.

Australian politics has neither the willpower nor the foresight to battle either the coal or the fuel lobby.

The current government has already started watering down its initial fuel efficiency standards: https://www.abc.net.au/news/2024-03-26/vehicle-efficiency-st...

Although an unintended consequence tax write off (which saw a massive percentage increase of US style 'trucks' on Australian residential roads) is being cut back: https://www.smh.com.au/politics/federal/hate-all-the-monster...

Australia goes incredibly slowly in the right direction because Australians, like most Western countries' citizens, as-a-group, have their heads in the sand about the effects of the lifestyles to which they've become accustomed have on the world around them, and they're ably supported in this thinking by irresponsible media and opportunistic politics/politicians.

Norway is the only country in the world that is filthy rich in natural resources that has somehow prevented it from fucking them up politically.

Theyre clearly doing something right but it's something nobody else seems to be able to replicate.

Iraq, Libya, Saudi Arabia, Subsaharan Africa, Venezuela, etc. - this is what it is typically like to be very, very rich in natural resources.

Even Australia's political system has been badly affected by being resource wealthy - look at the influence Gina has.

This is the resource curse.

You don't even have to nationalise it. Just tax it properly.

As fossil fuels decline in importance, they will have less money to bribe politicians with, and the renewables will have more.

politician bribes tend to be in the millions of dollars, while profits can be in the billions of dollars.

In a life or death situation for an industry, they can exert literally 1000x the political pressure before making losses.

Well, then I guess they have to make sure they don't decline in importance, right? And currently they're quite successful at doing that: https://www.theguardian.com/environment/2024/mar/28/oil-and-...

You also have to build hundreds of billions to trillions of dollars worth of power transportation infrastructure.

Which is totally affordable, not that big a deal.

Another way to look at it is $10,000s a person over a few decades.

Working on it :-) Hydrogen/Ammonia will help significantly.

How does a very inefficient conversion from electricity to hydrogen to electricity help?

It allows you to store large amounts of energy when energy is cheap.

Why not use batteries and get twice the efficiency?

Because cost and efficiency are related but not the same.

Don't need to convert it back. Hydrogen is used for example in steel making. Green steel eliminates most of the emissions from the steel making process.

While a lot of these processes may not be efficient for electricity generation, using them to clean up very emission intensive industries is a process that needs to be undertaken to reduce emissions worldwide.

The steel industry consumes 5.9% of global energy and emits 6-9% of global CO2 emissions.

Interesting that this is achieved with only a 5% overbuild. The simulations I have seen to get to 100% for Europe and North America without long term storage have used a 200% (aka 3X) overbuild.

Probably partially due to Australia being a good place for sun and wind, and partially for targeting 99% rather than 100%.

If they are using peakers for the last 1%, one can instead fuel those peakers with e-fuels. The low round trip efficiency of e-fuels doesn't matter much if they're providing just 1% of the total.

That could be the difference between "near 100%" and 100%. Or it could be because Australia has good renewable resources.

This paper is a similar analysis but for the US, check Fig. 3. As you go from 97% to 100% renewables, the overbuilding requirements blow up.

https://sci-hub.se/10.1039/c7ee03029k

That conclusion assumes no long term storage. Including hydrogen drastically reduces the overbuilding required. Put another way: if you overbuilt that much, you can make hydrogen for basically the cost of the electrolysers, since the input power is often free.

You are correct that you can't create a stable, resilient grid just with intermittent renewables, you need storage.

But I don't think anyone has demonstrated long-term storage at grid scale, capable of storing power across seasons, which is needed in many areas. To be feasible the storage system has to be cheaper than maintaining some fossil fuel plants.

I haven't seen much about promising hydrogen storage systems.

> But I don't think anyone has demonstrated

Arguments like this really annoy me, if it's clear there's not a serious obstacle. It's just a "nothing can be done for the first time" argument.

I'm not saying it can't be done. I'm saying it hasn't been done yet. How about we try it before pretending that we can shift to 100% renewables or before legislating transitions that we don't know how to accomplish.

Hawaii is trying hard, but it doesn't seem to be going well with the grid becoming less reliable. BTW, this video is a solid overview of the power situation in Hawaii: https://www.youtube.com/watch?v=bbECmVdyWlQ&themeRefresh=1

I believe parts of the Azores have tried, but have not been successful.

I would be very interested in pointers to successful projects in this area.

I don't like how we talk about 100% renewables as if failing that means failure.

I'm happy with 90% renewables, a much easier goal, while we figure out the diminishing marginal returns later as technology breakthroughs and cost curves do the work for us.

Our objective is to minimize the area under the curve of future emissions. It's not "net-zero" in the abstract. Net-zero is just a proxy for the true objective. Getting to 90% renewables soon means less emissions (while being cheaper) than waiting an extra 10-15 years for 100% nuclear.

I'm not entirely sure what you mean by 90%. 90% of what?

You can't just have 90% of power generated by renewables and 10% by fossil fuels because there are times when you get 0% from renewables and so your fossil fuel plants need to provide 100% of the power. So you spent all that money on renewable infrastructure and didn't even get the benefit of shuttering your fossil fuel plants.

90% of power generation on average.

What you've written here isn't persuasive. Are you trying to say that keeping gas peaker plants as a backup will mean renewables are more expensive than nuclear? Where is your analysis that fleshes that out?

Especially when a simply cycle turbine plant has a capital cost per kW maybe 5% that of a nuclear plant.

It's harder to do it on islands with only a single weather system than on continents which have diverse weather systems.

You need a significantly higher capacity (read: expensive) grid to get continent-scale weather diversity.

> I'm not saying it can't be done. I'm saying it hasn't been done yet.

So, what point are you making then? That because it hasn't been done it shouldn't be done?

In any case, there's a perfectly fine explanation about why it hasn't been done: people largely can burn cheap fossil fuels and not have to pay for the negative externalities that imposes on the world.

You are trying hard to misunderstand me. Don't communicate as if it is a solved problem if your solution has yet to be actually been built and successfully demonstrates the feasibility of the solution.

I'm not sure how to interpret your last sentence. A demonstration project, especially subsidized by the government, doesn't need to adhere to any sort of market pressure regarding the price of fossil fuels.

It's a solved problem in the sense that it involves components that are all understood to work, integrated. This is the surest kind of innovation.

Now, we don't know how cheap it will ultimately be once these things are integrated and run down their experience curves. But pretending there's any serious doubt that they would work is more dishonest than arguing they would.

Your definition of "solved" is quite a bit different than my definition of "solved". Especially if you are going to just pretend that the economics aren't to be included in the solution.

Yes, your definition of "solved" is useful for nothing but obfuscation and denial. Mine is useful for planning what to do.

Come on.

https://news.ycombinator.com/newsguidelines.html

> it's clear there's not a serious obstacle

However, building grid-level storage is a serious obstacle

> It's just a "nothing can be done for the first time" argument.

No. The "it's easy, just build a lot of storage" argument is magical thinking.

How is it magical thinking? The plan is very explicit and all the parts are available: We build gas peakers that are H2 compatible; we build electrolizers; we upgrade the existing methane storage to be H2 compatible; we store hydrogen and burn it when needed. There is no "magic" there. Hydrogen is needed anyway to decarbonize industrial processes, so the cost for the infrastructure has to be paid.

You're omitting one tiny detail: we just have to build that at scales never attempted before.

Also, omitting the tiny detail of how complex it is to store hydrogen which you assume is the way to store energy.

We literally have the infrastructure to store TWh of methane, so we have already built at the necessary scale in the past. It is also not terribly complex to store hydrogen if you're okay with losing a few percent per year. You might be thinking of cryogenic hydrogen storage, which is definitely not the plan.

Everything is simple if you ignore everything. Because in the mind of renewable proponents all that grid-level storage is either already available or can be easily and cheaply built, no biggie.

"We have existing infra" ignores that this infra took decades to build.

"We know how to build" ignores that the storage costs can vary between 7 EUR/kg and 1040 EUR/kg [1]

and so on and so forth.

The capability for wishful thinking in renewable space is staggering.

Note: no one is saying it is impossible BTW.

[1] Great article: https://www.sciencedirect.com/science/article/pii/S036031992...

I don't think anybody ignores the costs. It's just that every other option is more expensive.

Yes, an energy system to supply the world is not a small thing, regardless of where the energy is coming from. The world is going to spend something like a quadrillion dollars on energy over the next century. There's a very large budget to do this.

I will note that the same hand wringing would apply to nuclear, only in nuclear's case it means we can't keep using today's burner reactors, since cheap uranium runs out. In contrast, we already have electrolysers (the pacing technology) at less than $3/W in China.

The thing is, that "hand wringing" is what renewable proponents always apply to nuclear. However, the moment you ask them about storage, "oh it's a solved problem"

No, what renewable proponents do is point out nuclear's egregious demonstated economic flaws. This is not a case of hypothetical problems, it's a case of actual repeated failure.

> is point out nuclear's egregious demonstated economic flaws

No, they don't. They point at an industry which was for decades was vilified, ignored and obstructed, and say "see, this is hard, costly, and nearly impossible"

The industry was for decades vilified and obstructed, but not ignored, because of the nature of the failure modes.

Mean cost vs. worst-case cost.

The mean cost of cleaning up nuclear reactors is tiny.

Eyeballing this graph: https://ourworldindata.org/nuclear-energy I think we've had around 100 PWh total generated by nuclear reactors over history?

There was only one Chernobyl ($340 billion inflation-adjusted), only one Three Mile Island ($2 billion adjusted), and only one Fukushima (probably around $200 billion adjusted).

If so, those accidents cost $542bn/100 PWh = 0.5¢/kWh, which is a trivial excess on even cheap (5¢/kWh) electricity: https://www.wolframalpha.com/input?i=%24542bn%2F100+PWh+in+u...

Unfortunately, two of those three demonstrate how expensive these can be when they go wrong, and that number is sufficient to just bankrupt quite a lot of countries — for example, Ukraine, which is where the Chernobyl reactor is, has a nominal GDP less than the cost of the Chernobyl cleanup: https://en.wikipedia.org/wiki/List_of_countries_by_GDP_(nomi...

> basically the cost of the electrolysers

Yes, that's the expensive bit.

The reason you don't get much of this already is exactly that the capital cost of electrolysers is very high because of the requirement for platinum electrodes. And big capital investments are not free.

Platinum isn't required for alkaline electrolysis.

The reason we don't have a lot of hydrogen right know is because we don't have a lot of surplus energy right now. It makes no sense to buy expensive equipment and run in only a few hundred hours a year.

We have huge amounts of hydrogen right now. At standard temperature and pressure, the amount of hydrogen made globally each year would occupy 700 cubic kilometers of volume. It's just that it's made overwhelmingly from fossil fuels, mostly natural gas (6% of global gas production goes to making hydrogen).

That this is being done instead of making green hydrogen is because CO2 from the fossil fuel process is not being taxed or otherwise forced to account for the negative externalities.

This also illustrates that producing hydrogen without CO2 release is not an optionally solvable problem. Without the ammonia made from hydrogen (which is where most of it is going) billions will starve.

The article itself makes the point that overbuilding the renewables massively will get you from 98% to 100%, but the consequences of that are increased cost and increased emissions, compared to just having some fossil-fueled peaker generation on standby.

Some of the US government plans involve getting to 95% carbon free electricity, then refocussing investment to electrifying anything that still uses fossil fuels as the cost/benefit will have tilted dramatically at that point, even for the harder to electrify sectors, and provide more bang for buck than fretting about the last percent of peaker plants.

The numbers I have seen assign a capacity factor of 0.1 for renewables, that would require 900% overbuild.

> The simulations I have seen to get to 100% for Europe and North America without long term storage have used a 200% (aka 3X) overbuild.

You don't need simulations. Right now solar+wind in Germany is at capacity that is 2x Germany's consumption.

Almost every day (and definitely every night) they burn coal and import electricity from other countries because, you know, night happens, cloudy days happen, quiet days with little to no wind happen.

I thought overbuild figures usually include capacity factors, putting Germany at something like 0.3x instead of 2x?

My guess is that a power grid engineer would include capacity factors, but I've never seen the mass media, politicians, or advocacy groups think like an engineer in this regard. Even making that adjustment it doesn't factor in seasonal variations. Not understanding these factors results in ignorant headlines like:

California just ran on 100% renewable energy, but fossil fuels aren't fading away yet https://www.npr.org/2022/05/07/1097376890/for-a-brief-moment...

Renewables are now way cheaper than coal https://energynews.us/newsletter/renewables-are-now-way-chea...

That's because they haven't done much storage yet. Which is to be expected, you want to leave that for the end because it's the most expensive bit. They're planning 15GW of 4-hour batteries by 2030.

https://blog.fluenceenergy.com/energy-storage-roll-out-can-s...

Just to give you a perspective, energy Germany needs is around 61 GW. It's likely to go up as people switch to electric cars.

Also, that article is make believe as every single graph and stat in it (and in the linked study) talks about the future. I'm afraid they are literally doing this extrapolation: https://xkcd.com/605/

I think it's mostly that overbuild is usually referring to capacity, and they've multiplied the generation.

I'd guess this works out roughly the same if you applied his scaling factors to the current capacity.

His 25% rooftop solar would be around 200% capacity given a 12% capacity factor.

This is great for homes, but one thing I keep thinking of is if one wants to run an aluminium smelter using renewable electricity you'd need a huge bank of batteries. I guess these would still need large hydro power.

But that's the thing if the market becomes more reliable, than larger loads become feasible, which means usage, and economics start to move in unforeseen directions.

We can build it next door to the carbon credit scheme!

https://www.sciencealert.com/shock-discovery-huge-carbon-cre...

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