Jenny ChaseOct 20

Time to make 2025 updates to my annual “opinions about solar” thread. If you like these, you might like the second edition of my book, Solar Power Finance Without The Jargon. A 30% discount code WSQ0437 is valid on publisher website until end of Nov 2025.

It's the book I should have read before trying to get a job in renewable energy. Reviewers describe it as “to the point, important, and taught me a lot” and “surprisingly entertaining, don’t be put off by the title”.

https://www.worldscientific.com/worldscibooks/10.1142/q0437#t=aboutBook

Show threadJenny ChaseOct 20

I have put out this thread once a year on X since 2017 and Mastodon / Bluesky since 2024. See 2024 thread below, and from there links to previous threads. So you can see what I got wrong, or at least changed.

https://mastodon.green/@solar_chase/113214911341855405

Some of these assertions will contain links to BloombergNEF content under a paywall. If you are not lucky enough to have access, you'll have to believe me that's what it says.

Also, I'm on maternity leave, so this thread is lighter on changes than in some years.

Jenny Chase (@[email protected])

Time to make 2024 updates to my annual “opinions about solar” thread. If you like these, the second edition of my book, Solar Power Finance Without The Jargon is out. https://www.worldscientific.com/worldscibooks/10.1142/q0437#t=aboutBook

Mastodon.green
Show threadJenny Chase
1. To opinions! Solar is the cheapest source of bulk electricity in many countries, and the quickest to deploy, and now you couldn't stop it being built if you wanted to. The limits to PV build in most places are grid access, permitting, and sometimes installation labour.
Oct 20 at 7:08amWeb
Show threadJenny ChaseOct 20
2. 20 years ago when I got this job, I thought maybe solar would one day be 1% of global electricity supply. In 2024 it was about 7% worldwide, and rising fast. You can see this eating into fossil fuel power generation in, for example, Europe.
Show threadJenny ChaseOct 20
3. Solar will not solve every problem. But the biggest problem is that our civilisation relies on digging up fossil carbon and burning it, which is destabilising the climate, which multiplies a lot of very unpleasant threats. Solar is part of stopping us needing to do that.
Show threadJenny ChaseOct 20
4. We don’t need a solar technology breakthrough. The challenges to building solar are usually getting a grid connection and planning permission, or increasingly, power price cannibalization. Of which more later in thread.
Show threadJenny ChaseOct 20
5. Solar modules now cost 8.9 US cents per Watt (higher in US, India due to trade barriers). Solar panels are cheaper than most ordinary fencing materials. For rooftop installs, non-module cost is still $0.50-3.00 per Watt, so further module price declines make little difference.
Show threadJenny ChaseOct 20
6. These prices mean that few makers of solar modules are profitable right now. If manufacturers stop selling at these prices, they will permanently lose customers. They are locked into a game of chicken. There will be bankruptcies and eventual price stabilisation.
Show threadJenny ChaseOct 20
7. Solar manufacturing has always been a horrible business, and that’s unlikely to change. It’s very commoditised, barriers to entry are fairly low, and incremental improvements in cell and module tech make factories obsolete in less than four years.
Show threadJenny ChaseOct 20
8. India and the US have solar import tariffs, so modules are pricier there (~15 and ~27 cents/W respectively). Both countries are subsidizing local manufacturing capacity. This is a perfectly good strategy as long as it doesn’t slow down their energy transition, but...
Show threadJenny ChaseOct 20
9. Thank goodness we’ve collectively stopped the nonsense of boasting about "lowest ever solar auction prices", most of which were Middle East opaque transfer prices or had other features. PV power prices below $25/MWh unsubsidized are still too low. This is very cheap power, but solar still does cost money.
Show threadJenny ChaseOct 20

10. 'Power price cannibalization' for solar happens because solar plants in one area all generate at the same time. This means that they reduce the price of power at that time, “cannibalizing” their own revenues.

11. High solar penetration resulting in power price cannibalization also affects other power plants, but not as much as it affects solar, because solar plants generate most at times when solar is pushing the price down most. This will inhibit further solar build.

Show threadJenny ChaseOct 20
12. This is already obvious in Spain, California, Australia and even Germany. Now that the global liquefied natural gas price hike related to Russia invading Ukraine in 2022 has eased, lower power prices drive solar developers to seek long-term contracts again.
Show threadJenny ChaseOct 20

13. By 2030 most countries will have spot power prices of zero in sunny hours. This will be passed on to end consumers, to encourage them to shift power demand to sunny periods by electric vehicle and battery charging, preheating, precooling, etc.

14. Low power prices may be great for consumers but they are very bad if you're trying to build more clean power plants. Without demand-side flexibility, the energy transition will fail before fully pushing fossil fuel out of the mix.

Show threadJenny ChaseOct 20

15. It's very easy to say "but batteries!" and those are definitely part of the solution. California has over 14GW of batteries in a grid with roughly 50GW peak demand, and the reliability of the grid has improved as its carbon emissions go down.

16. ...but batteries are still small. In 2024, about 181GWh of lithium-ion stationary storage was deployed worldwide, plus 974GWh lithium-ion batteries in vehicles. (https://www.bnef.com/insights/37025).

Lithium-Ion Batteries: State of the Industry 2025 Dataset

This dataset provides an overview of electric vehicle and stationary energy storage battery demand and performance metrics across various sectors and regions. It acts as a summary of the data that BloombergNEF has on the battery industry in 2025.

BloombergNEF
Show threadJenny ChaseOct 20
17. Small-scale batteries are a thing too, even though the economics don’t always make much sense. 2024 battery attachment rates – proportion of residential PV buyers who get a battery too – were ~ 80% in Germany and Italy, ~ 50% in Switzerland, UK and California.
Show threadJenny ChaseOct 20
18. It is very difficult for installers and financiers to become large and long-term profitable in the residential solar and storage market. Margins are thin and there are diseconomies of scale.
Show threadJenny ChaseOct 20
19. In general this is a problem for solar, both for manufacturing and downstream: a distributed industry with low barriers to entry, and therefore few large firms, has little lobbying power. Industry associations work against this to represent the interests of renewables in politics, against those of more naturally consolidated industries like fossil fuels, but they do have a structural disadvantage.
Show threadJenny ChaseOct 20
20. There is no way we can build a big enough battery to shift energy from summer to winter. The economics of battery storage are nearly impossible at one cycle a year.
Show threadJenny ChaseOct 20
21. Everyone is defining 'long-duration storage technology' wrong. It's not about 6 or 8 hours — you can do that with lithium-ion and probably will — it's about having the capex to add more GWh of capacity decoupled from the capex of adding more GW.
Show threadJenny ChaseOct 20
22. Examples of real long-duration storage technologies are pumped hydro (reservoir size is decoupled from turbine capacity), or where the storage medium is big tanks of molten salt, or hot rocks. But all of these do still cost a lot of money if they are only cycling once per year.
Show threadJenny ChaseOct 20

23. Lithium-ion will probably continue to be the dominant battery technology. High prices for lithium in 2022-2023 drove interest in sodium-ion, and there are still products coming out, but new lithium production capacity has brought prices back down and so the impetus to switch has been reduced.

(The cure for high prices was, it turned out, high prices.)

Show threadJenny ChaseOct 20
24. We oughtta be building more wind generation capacity. Seriously, solar will get built anyway, but wind needs some help, and wind blows in the dark and in the winter. It doesn’t help that solar pushes down power prices and generates renewable energy credits (where relevant), which hurts wind farm economics.
Show threadNicole SullivanOct 20
@solar_chase I wondered if, on the scale of a house, a large concrete slab could be insulated and heated during the day to release heat at night? In places where it is sunny even in winter, like California. Maybe heat pumps are too efficient to make that make sense.
Show threadBjörn ❄️ StarkimarmOct 20

@stubbornella

I mean, that's basically how many houses work in Europe (but the concrete/bricks are also in the walls).

@solar_chase

Show threadSu_GOct 20
@solar_chase
What about Buckminster Fuller’s suggestion re using the N-S halves of the globe to even out power generation & distribution? When one half sleeps at night the other half is generating (a simplification but you get the idea). 🤗
Show threadEarth NotesOct 20
@Su_G @solar_chase See #4!
Show threadsoaprootOct 20
@solar_chase I'm curious whether this will be higher in California for 2025 as the remaining NEM2 projects make it through the system (disclaimer: I don't have details of NEM2 vs NEM3 by date handy, just that 50% sounds low given NEM3 incentives)
Show threadkravietz 🦇Oct 20
@solar_chase

Thanks for this thread, loaded with useful data! A question: what do you make of the fact (IEA) that 80% of the whole PV supply chain is controlled by one country - China - and therefore the today’s PV price is a product of Chinese subsidies, forced labour and poor environmental standards?
Show threadSamuelJohnsonOct 20
@kravietz @solar_chase Seriously? China isn't North Korea. It has lifted more people out of poverty than any country in my lifetime. It hasn't done so with forced labour. Its environmental footprint is improving. China's not perfect, sure. But has it overthrown democratically elected governments it didn't like, like the US and UK? Claimed global warming was a hoax and done its best to ramp up hydrocarbon use? We should be grateful for the lifeline & avoid cutting off our noses to spite our faces
Show threadkravietz 🦇Oct 20

@samueljohnson @solar_chase

As a reminder, communist China has illegally occupied Tibet, murdered and starved to death millions of people during Cultural Revolution, right now it’s pursuing violent prosecution of Uyghurs and makes heavy use of forced labour. It also enforces strict censorship and many other attributes of a totalitarian state.

If you control 80% of market, you’re not “throwing a lifeline”, you’re a practical monopoly. And monopolies always do what monopolies do, that is abuse their monopolist situation, which is what China just started doing on rare earth metals market:

https://www.csis.org/analysis/chinas-new-rare-earth-and-magnet-restrictions-threaten-us-defense-supply-chains

In case of EU, it’s also about fundamental values - if we say our socio-economic model is the best and our environmental laws should be copied by everyone, then we should put the money where our mouth is and prove it in practice.

That is, run mining and industrial operations inside EU at low environmental footprint rather than import everything from a totalitarian state “because cheap”. The current policy just ridicules what we say.

China’s New Rare Earth and Magnet Restrictions Threaten U.S. Defense Supply Chains

China has imposed its most stringent rare earth and magnet export controls yet, restricting products with even trace Chinese content. This bolsters its leverage ahead of the Trump-Xi meeting and heightens risks to U.S. defense and semiconductor supply chains.

Show threadSamuelJohnsonOct 20
@kravietz @solar_chase I've spent time in China and don't need any reminders about Tibet or anything else on the downside. The West doesn't have much in the way of a moral high horse and if China has a near monopoly on solar its precisely because of Chinese long term thinking. As for control of minerals China is perfectly entitled to use geopolitical tools at its disposal. The US hasn't hesitated to do so. US: good, China: bad is tripe. Others will make choices on a more sophisticated basis.
Show threadkravietz 🦇Oct 20

@samueljohnson @solar_chase

If you haven’t noticed, I’m not living in the US so I’m not quite sure why you bring this unrelated third party to this discussion.

And, as you said, if “China is perfectly entitled to use geopolitical tools”, this also implies that EU is entitled to use all tools at its disposal to avoid repeating the Gazprom 2021-2022 fun, isn’t it?

Show threadSamuelJohnsonOct 20
@kravietz @solar_chase The US isn't an unrelated 3rd party. It was until recently supposedly an ally and the co-guarantor of European security. Yes, the EU should use its own geopolitical power as it sees fit, though this hard to do given the nature of the entity. German purchase of Russian energy was always questionable but the effort to integrate Russia economically given German moral debt wasn't. It failed. That was not Germany's or the EU's fault and will accelerate decarbonisation.
Show threadkravietz 🦇Oct 20

@samueljohnson @solar_chase

Funny that you use the old Steinmeier’s “moral debt” fallacy in a way that is very favourable for Putin’s Russia while completely ignoring the numbers that indicate that the actual largest “moral debt” Germany owes to Poland, Belarus and Ukraine, the countries Germany had traditionally been throwing under the bus whenever it comes to pleasing Putin.

Show threadSamuelJohnsonOct 20
@kravietz @solar_chase I am unfamiliar with Steinmeier and made no reference to relative moral debt. I don't consider the idea of moral debt fallacious, but then I'm a citizen of a country subjected to foreign oppression for hundreds of years. Nor, apparently do you, with your score keeping approach to crimes against humanity. Trade and economic convergence are how we have tried to move past hostilities in the EU (once evil is defeated, as Putin must be).
Show threadkravietz 🦇Oct 20

@samueljohnson

I was referring to this once famous 2007 article by Steinmeier, which was a kind of canonical text in the Wandel durch Handel thinking of German political class:

https://internationalepolitik.de/de/verflechtung-und-integration

When reading it today, one can only exclaim on most paragraphs “OMG how naive he was!”

Steinmeier’s problem was of course that he was brought up in the combination Christian morality and Germany’s post-war complex of guilt that he internalised so deeply, that he was unable that human societies developed very different moral systems out there. One of them is the predatory model, mastered by Putin. Everything else is the consequence of this blindness - if you hand a slice of bread to a crocodile because you only know horses, it will always end up in one way.

@solar_chase

Verflechtung und Integration

Der Erfolg der Integration Europas – durch Verflechtung von Interessen deren friedlichen Ausgleich zu erreichen, zudem Wohlstand und soziale Gerechtigkeit – macht die Europäische Union zum weltweit bewunderten politischen Modell. Jetzt gilt es, diesen Erfolg auch auf die europäische Nachbarschaft auszudehnen und ihn global zu verankern.

Internationale Politik
Show threadSamuelJohnsonOct 20

@kravietz Thanks. I note however, that Poland has a gas pipeline to Germany and can therefore be regarded as being willing to trade with former enemies, no doubt for pragmatic reasons. Here in Ireland the British in Northern Ireland (the local Donbas) refer to the natives as crocodiles. It's one of the reasons they will not tolerate street signs in the language of the natives or anything else they consider "feeding the crocodiles".

We are, in fact, all mammals.

Show threadkravietz 🦇Oct 20

@samueljohnson

Oh, Poland and Germany are today mutually the largest trade partners! Our two countries are the best demonstration of idea that cooperation is much more beneficial than conflict, and this is one reason why I believe the whole debate on reparations is just a stupid smoke screen - Germany long ago paid billions of euro to Poland as part of the mutual trade.

As for the wonderful British class culture, I’m myself living in the UK and have a chance to watch it live daily 😉 When a random person at a pub asked me “do you own or do you rent” immediately after “what’s your accent” I was only disgusted for the first time, then I got used to it 😆

Show threadkravietz 🦇Oct 20

@samueljohnson

As for the moral debt, I don’t think it works anywhere beyond the individual level. Above that, the level of complexity is such that you must employ instruments designed for handling that complexity - that is negotiation on legal terms.

In all kind of state-level oppression, you must have some kind of closure. For most nations - and Poland and Ireland were in the same boat here - the ultimate closure was regaining independence. From that moment, you’re on your own and you’re the only party responsible for the state of your country.

In Poland that happened twice - 1918 and then 1989. In both cases nobody had any illusions that the occupiers will pay any kind of reparations or something simply because they - thank God - collapsed.

The case of Germany is more interesting because German reparations for Poland were rejected (!) by Soviet Union on Poland’s behalf (USSR itself, of course, happily took $12b in today’s money in reparations for itself).

Today this serves some Polish populist politicians to demand “reparations” which, 80 years later, sounds absurd to me. This dispute only serves heating the political polarization inside Poland, but that’s its very purpose - justify your inability to manage the country by some ancient events.

The people who live in Germany today are completely different people than those who started the war, and the people in today’s Poland are completely different people than those who were killed back then. There’s still some questions from WW2 that are not fully resolved (like theft of art), but these can be only dealt on legal level due to their complexity.

For the same reason I consider the US “white guilt” concepts equally absurd and only serving disintegration of the society and actually bringing back the old racial divisions.

@solar_chase

Show threadJenny ChaseOct 20

@kravietz it's largely untrue; China has not directly subsidised solar manufacturers for over a decade, the allegations of forced labour relate to a very small section of the supply chain which has a lot more to do with other industries like steel, and environmental standards in China have come a long way, as have salaries.

Basically Chinese companies have got good at making solar panels, and good solar panels are the main reason for any climate optimism.

Show threadkravietz 🦇Oct 20

@solar_chase

Yes, but the 80% control over the PV supply chain remains a fact. IEA clearly indicates this a long-term risk for any infrastructure investment. And right now, as expected, China started pursuing the existing export license mechanisms.

Regarding environmental standards, current Chinese ETS price is what - $15 - while EU ETS price is $80, which tells you all about it.

Show threadScooter Oct 20
@solar_chase I did a doubletake at this graph. Is that ~20% wind/solar for all of Europe??
Show threadJenny ChaseOct 21
@scooter approximately, yes!