zerocalories asks, 'Why bother? This is like paying off a debt with low interest early. A poor financial decision.'

this presupposes that the energy mix is changing because of costly government subsidies, and if that presupposition were correct, it would be a very reasonable comment

but that's not what's happening. countries aren't hitting their targets because the local government subsidies are more successful than expected; they're doing it because renewable energy (and, in some cases, energy efficiency improvements) is cheaper than fossil fuel in most of europe now, and has been for several years now, so companies and individuals invest in renewable energy instead of fossil-fuel production capacity, even without local government incentives

this is primarily because of capitalism in the people's republic of china, strongly supported, of course, by the so-called communist party of china. past subsidies in some european countries and the usa are of course also historically important

it would be easy to misunderstand that the chinese government is subsidizing the european energy transition, so that as europe switches over to renewables, it will cost the chinese government larger and larger amounts of money until finally they take measures to stem the flood. but that is not the case; the chinese renewable energy producers are profitable on their own terms. there was a price-fixing cartel announced at davos in 02019, which kept the price of solar panels at about €0.20 per peak watt of low-cost panels from the end of 02018 to the end of 02022 (or €0.29 for mainstream higher-efficiency panels). if we believe https://www.solarserver.de/photovoltaik-preis-pv-modul-preis... that price has now fallen to €0.09 per peak watt for low-cost panel modules, €0.14 per peak watt for mainstream, so the cartel has evidently fallen apart; i infer that government support was helpful for holding it together for so long, but presumably at the end the panel producers' gross profit margins were close to 50%, like copyright-mafiaa rentiers. such high profit margins create enormous temptations to undercut other cartel members to win market share, so cartels in markets rapidly climbing up the experience curve tend to be very unstable

(wind turbine prices have also been falling, but the available wind resource is much smaller, and exploiting it is more often politically infeasible.)

suppose you can borrow money at 4% apr to build solar farms, and you somehow manage to keep the total cost of building a plant (inverters, cables, installation, etc.) to twice the panel costs, which has been roughly the historical average (https://ratedpower.com/blog/solar-farm-costs/), and you manage to site the plant somewhere with a capacity factor of 16%—not the 29% california gets, nor the 10% maine and germany get (china too for some reason!), but somewhere in between. €0.09 per peak watt becomes €0.18 per peak watt and €1.13 per average watt, and at that 4% apr, each average watt costs you €0.045 per year in interest. but an average watt is 8.77 kilowatt hours, because a year is about 8770 hours

so that's €0.0051 per kilowatt hour

fossil-fuel power usually costs around €0.03 per kilowatt hour, 500% more. it costs even more when it's being burned in an inefficient mobile internal-combustion engine. it can't compete, except where it's the only option. it can't even compete in germany, much less in india, perú, tunisia, and indonesia

unlike wind turbines, photovoltaic solar panels scale down very well; you can get a 200-watt-peak panel. this greatly limits the options incumbent utility companies have to protect themselves from competition from this radical threat; if they try to keep their prices high to pay off the debt they owe on their coal and oil plants, many of their customers will install local generation capacity, reducing their customer base to one even less able to pay off the large fixed costs—the much-feared 'utility death spiral', a phenomenon which so far has not materialized

this is also why african, asian, and american countries with no emissions targets won't just replace european consumption of fossil fuels

it is difficult to overstate the importance of this change for human economic development. the last time the price of energy dropped so much was sometime in the early 19th century, and energy is still profoundly important to the economy, despite the migration of heavy industry away from rich countries. how will this near-order-of-magnitude reduction in the cost of energy affect the relative prices of goods and the possibilities for human development? how will it alter geopolitics?

and given that the price has been falling like this for 15 years (solarserver listed a price of €2.17 per peak watt in may 02009, 24× higher than today, an average halving time of about 3.2 years—the cartel bubble merely paused progress along the trajectory to which the price has now returned) it's likely that it's not done falling yet