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.

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.

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).

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.)

29. Electrification of transport is far better than biofuels; solar plants can run an electric car on a small fraction of the land used to grow fuel to run a biofuel car.

30. Decarbonizing aviation is hard. The CEO of Lufthansa said in 2023 that running its fleet on sustainable aviation fuel made from electricity would take half Germany’s current electricity demand. BNEF thinks this an underestimate.

32. Heatpumps are better for heating homes than hydrogen, but in seasonal climates like northern Europe will exacerbate the seasonal demand and supply mismatch for solar. We need to build wind and probably nuclear as well.

33. How mismatched is European seasonal solar supply and electricity demand? Well, here is the situation for my fully electrified house in Switzerland with 13.2kW of solar, a heatpump and an EV. I would have needed about 122kW of PV to be self-sufficient across December.

36. We’re finally getting serious about net zero carbon. Getting that last 5-20% of carbon out of power will be hard, and require some expensive solutions. The first 80-95% is easy-ish but we're getting on with it.

37. You can be cynical about government and corporate net zero emissions targets if you like, but they're a lot better than no net zero emissions targets.

40. There are signs that solar is reducing fossil fuel burn in poorer countries, for example Pakistan — which has no significant government support for solar but has built over 25GW just in response to high prices for power and fuel for irrigation.

41. This has interesting and not uniformly positive side effects. Pakistan may be the first market to see a true 'utility death spiral' where customers who can go solar do so, leaving other customers to pay for the grid, raising power prices..

43. Data centers are increasing power demand, but let's keep a sense of proportion. BNEF estimates total electricity demand from data centers of 373TWh in 2024 (1.2% of global generation) and expects this to increase to 1,596TWh (4.4% of global) in 2035.

This is a source of some disappointment to renewable energy project developers.

(https://www.bnef.com/themes/t0hlzngpl47w00 )

45. Some governments are definitely out to fight against a better future.

46. Achieving a net-zero energy transition, for most countries, will not look like winning a war or marching into a capital waving flags. It will be the ability to say "no thank you, we do not want what you are selling" to the petrostates, and walking (or cycling, or taking an electric bus, or driving an EV) away.

47. While moving to a circular economy with 100% recycling rates is essential in the long run, it’s not a challenge for PV in particular; few PV panels have been recycled to date only because the vast majority are still in use. It can be, and is, done.

Volumes are still tiny compared with most things we also have to recycle.

48. Floating solar, agrivoltaics, balcony solar: yes you can put solar panels on anything that stands still long enough. If you have a lightweight encapsulant, you can also put them on something that moves.

The decision comes down to: in this use case, will the solar panels get in the way, and will they get broken by normal activities?

49. 'Agrivoltaics' is defined as 'solar that gets preferential legal / permitting treatment applying to agrivoltaics projects' and therefore the definition is local. It's not really a different technology and so a general statement on it is not really possible.

It's harder to harvest crops and work land under solar panels, so many owners may quietly drop the farming bit once support is secured.

50. Grazing sheep under solar panels should not qualify them for agrivoltaics support. Solar subsidising sheep farming is not particularly an environmental plus.

(Some crops do seem to work well with PV, for example shade-tolerant berries, and in some climates, vegetables for which growth isn't limited by light availability. Farming involves a lot of optimising for local conditions and so often the answer to 'what works?' will be 'it depends....').

51. For 6 years I have been refusing to get excited about perovskites until a perovskite company can disclose a commercial partnership with a named major module manufacturer. They have now. Still not excited.

Crystalline silicon is honestly good enough.