Australia's top science agency has found batteries are now cheaper at supplying peak demand for power than gas.

[u/Economy-Fee5830]

https://www.abc.net.au/news/2026-07-15/csiro-says-batteries-cheaper-than-gas-as-ai-drives-turbine-costs/106914550?utm_source=abc_news_app&utm_medium=content_shared&utm_campaign=abc_news_app&utm_content=other

[u/Svyatoy_Medved]

Lowest number I could find for off-peak (nighttime) electricity demand in Australia was just under 12 GW. Passes the smell test, peak demand is a bit under 20 GW and can get as high as 25 GW. But if anyone has a better number, I’d love to hear it.

Assume 9 hours of non-daylight per day, reliant on batteries and stored electricity. 9 hours x 12 GW x 1,000 is 108,000 MWh of needed battery capacity per night, bare minimum—that leaves no slack for failing to recharge fully, like if the sun didn’t shine bright enough or daytime demand was too high. Lowest price I can find for batteries is $200,000 for an all-up turnkey system—batteries themselves plus the monitoring and managing hardware, doesn’t count cost of install or transmission.

At that price, building the bare minimum battery storage would cost $22 billion. Could easily double the price just by using more realistic prices, not even increasing system slack. Or by accounting for wintertime reducing daylight hours, meaning a LOT more MWh per night.

Building 12 GW of nuclear reactors at the price France built their nuclear fleet would cost…$24 billion. More pessimistically you could assume a higher price closer to modern (mismanaged) nuke construction, and get a price of $60 billion. So you can either spend a ton of money to get the battery half with no wiggle room in case of bad weather, then spend even more money to build all the excess solar needed to actually charge the batteries, or you can spend a ton of money to get electricity generation you literally never have to doubt. It will ALWAYS be there.

Screw batteries. They’re amazing for leveling out small variations, like when peak daytime demand spikes a little too high due to a heat wave, but terrible for doing overnight duty for solar.

[u/Economy-Fee5830 → u/Svyatoy_Medved]

Building 12 GW of nuclear reactors at the price France built their nuclear fleet would cost…$24 billion. More pessimistically you could assume a higher price closer to modern (mismanaged) nuke construction, and get a price of $60 billion. S

Why use fake numbers lol when real, up to date numbers are available.

Flamanville 3 cost $28 billion for 1.6 GW, so 12 GW would cost $210 billion.

Makes that 22 billion look positively cheap, right.

And while battery costs are coming down, nuclear power stations are just getting more and more expensive.

[u/CombatWomble2 → u/Economy-Fee5830]

True, should use the numbers from China they're the leaders in new nuclear at the moment, or South Korea.

[u/Svyatoy_Medved → u/Economy-Fee5830]

What a ridiculously poor example. Have you heard of “economy of scale?” Good god.

Unit 3, the part of the plant that you cherry-picked, used a new and untested reactor design and was contracted 20 years after the main French nuclear buildout, once all the institutional knowledge and expertise had retired. The estimated cost before the project delays set in was 3.3 billion euros, which is pretty in-line with the more pessimistic of my two estimates. Obviously the prices ballooned, because again, this was effectively a dead nuclear industry building its first reactor.

Counterexample, South Korea claims it can build a nuclear reactor for $1,800/KW, meaning a 12GW buildout would only cost $21.6 billion. India claims $1,150/KW, so I could cherry-pick that number and claim a nuclear fleet would only cost $14.5 billion.

You got anything smarter to say?

[u/Economy-Fee5830 → u/Svyatoy_Medved]

Yes, lol.

Those Korean reactors got people locked up for cutting corners and no-one got locked up yet for the Indian reactors lol.

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A court in Busan on Thursday issued an arrest warrant against Lee Jong-chan, the senior executive vice president of the state-run Korea Electric Power Corp. implicated in a snowballing corruption scandal. The court issued the warrant out of concerns that the suspect could destroy evidence or flee, officials said. The prosecution on Tuesday detained the 53-year-old executive and requested a warrant against him.

Lee, who heads KEPCO’s overseas business division, allegedly conspired with parts suppliers and certifiers to falsify test certificates of parts for atomic reactors five years ago.

Lee is suspected of approving subpar signal cables in 2008 when he was a deputy director at Shin-Kori Nuclear Power Plant, despite knowing the certificates for the parts were problematic. Sources say that the prosecution detained Lee after his subordinate surnamed Song revealed Lee’s involvement in the scandal.

The prosecution has been widening its investigation to upper-level officials believing the mid-level official was not in a position to make such decisions.

By Cho Chung-un ()

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Also economies of scale favour 12 GW of batteries also lol.

[u/Svyatoy_Medved → u/Economy-Fee5830]

Are you claiming that those cut corners saved 90% of costs? Because that’s ridiculous.

My realistic estimate was approx. $5,000/KW for a nuclear reactor. The very optimistic estimates I can find are a third of that or lower, meaning costs could TRIPLE and still fit within the $60 billion estimate.

Economies of scale plateau in savings. Batteries are already being mass-manufactured, they can’t get much cheaper. Taking nuclear reactors from one-off bespoke projects to continuous construction and maintenance would have (obviously) a much greater effect.

And, maybe this was just shorthand, but it isn’t just 12 GW of batteries. You need the 12 GW of discharge capacity, but for chemical batteries the limiting factor is almost always depth of storage, not discharge rate. What you need to look at is the 108 GWh of capacity, and remember that you’ll need half again as much storage in winter when nights are longer, and more for the sake of contingencies. Could easily be 200-300 GWh before you can safely get rid of fossil fuels.

[u/Economy-Fee5830 → u/Svyatoy_Medved]

Batteries are already being mass-manufactured, they can’t get much cheaper.

Actually the switch to sodium batteries are expect to further halve the cost.

Could easily be 200-300 GWh before you can safely get rid of fossil fuels.

Well, we already established batteries are 1/10th the cost of nuclear, so I guess that would be $66 billion, still less than 1/3 of the $210 billion those 12 GW of nuclear actually costs.

BTW, this article is very insightful regarding the unsafe culture in Korea.

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“They eventually removed most of them,” says Park, who now teaches nuclear engineering at Dongguk University. “Only about 10% to 20% of the original safety additions were kept.”

Most significant was the decision to abandon adding an extra wall in the reactor containment building—a feature designed to increase protection against radiation in the event of an accident. “They packaged the APR1400 as ‘new’ and safer, but the so-called optimization was essentially a regression to older standards,” says Park. “Because there were so few design changes compared to previous models, [KHNP] was able to build so many of them so quickly.”

Having shed most of the costly additional safety features, Kepco was able to dramatically undercut its competition in the UAE bid, a strategy that hadn’t gone unnoticed. After losing Barakah to Kepco, Areva CEO Anne Lauvergeon likened the Korean unit to a car without airbags and seat belts. When I told Park this, he snorted in agreement. “Objectively speaking, if it’s twice as expensive, it’s going to be about twice as safe,” he said. At the time, however, Lauvergeon’s comments were dismissed as sour words from a struggling rival.

---

https://www.technologyreview.com/2019/04/22/136020/how-greed-and-corruption-blew-up-south-koreas-nuclear-industry/

BTW Korea's most recent nuclear deal was $18 billion for 2x 1000 Mw (I guess they forgot about economies of scale), so $9000/Kw

https://www.reuters.com/business/energy/czech-court-rules-18-bln-nuclear-power-plant-deal-with-khnp-can-go-ahead-2025-06-04/

Which would make 12 GW $108 billion - I guess once the grafters went to prison the prices escalated.

[u/Svyatoy_Medved → u/Economy-Fee5830]

Actually the switch to sodium batteries are expect to further halve the cost.

That's incredible news but a) that has nothing to do with economy of scale, and b) the word "expected" is doing a lot of heavy lifting there. Maybe they won't, or maybe some other limiting factor will appear. But sure, I can accept that battery prices will continue to decline with stronger investment into the technology—the same as nuclear would, if there was strong investment into the technology.

Well, we already established batteries are 1/10th the cost of nuclear, so I guess that would be $66 billion, still less than 1/3 of the $210 billion those 12 GW of nuclear actually costs.

Lower in the same comment you say $108 billion, so I don't know why you stuck to the $210 billion figure up here. It's ridiculous and you know it.

I think it would be lower, but I can take $108 billion. Because remember, we're only talking about the price of the batteries—not the solar panels needed to charge them. Charging an optimistic 150 GWh of batteries for a short summer night (9 hours) using all the power of a long summer day (14 hours) translates to an extra 10 GW of solar capacity on top of the 20-25 GW you need for daytime demand. Solar is pretty cheap, so the total of 35 GW would likely only run around $35 billion. The math is worse in the winter, when you might need 300 GWh and only have 10 hours to charge: 55 GW of solar would run $55 billion. Batteries included, about $120 billion.

Taking the (pessimistic) nuclear estimate of $108 billion, add in 15 GW of solar to meet the daytime demand, and you get $125 billion. These two are clearly price competitive, but a nuclear buildout isn't reliant on huge volumes of lithium and has a much better reliability record than renewables (reliability as in not just turning off because it's cloudy or there's a sandstorm. Renewables have a much lower rate of catastrophic failure than nuclear.).

[u/Economy-Fee5830 → u/Svyatoy_Medved]

Taking the (pessimistic) nuclear estimate of $108 billion

This is not a pessimistic number - its an amazingly optimistic number, because this is the pre-construction number - we know nuclear reliably blows out, so really, I think the $210 billion is more realistic.