Green is likely sponsored by Putin as a way of keeping Europe away from Nuclear and any other viable alternatives to Russian gas. (proof: Former German chancellor on board with Russian energy companies.) Not investing enough in Nuclear and solar is Germany’s biggest mistake.
There was de facto no investment into nuclear energy across all countries since the early 80s and it's beyond tiring to see online commenters adamantly trying to blame that on a scheming cabal of Green politicians, when Green parties never got beyond 10% of the vote in the elections. Yes, Germany prohibited the ban of new reactors in the earyl 2000s, but the truth is no one wanted to build them anyway and hadn't for a long time. Under the Schröder government, only two or three reactors were shut down and they were the oldest, had a meager output and weren't even profitable anymore. And the only way Russia influenced that was by mishandling Chernobyl. It's laughable to claim a country whose only high-technology export is nuclear technology is pushing others to abandon it.
Wrong. Wrong. Wrong. I'm tired of hearing this age-old propaganda tune over and over again.
Germany had plans (before the Schroeder government laid the foundation for the whole nuclear shutdown) to build new and more nuclear reactors. After the initial buildup phase from 1970 to the late 1980s (latest in operation was Neckarwestheim 2 in 1989 not counting test reactors, only 9 years before Schroeder, not really a "long time"), most good sites had a reactor or maybe 2 or 3. The plan then was to plan for replacing the oldest ones and add a few more to existing sites, starting in the late 1990s when the first reactors start to approach an age of 30, to be replaced by their finished replacement reactor on the same site at 40 before 2010. Those plans included pebble bed reactors (https://de.wikipedia.org/wiki/Kernkraftwerk_THTR-300 unsuccessful due to technical problems), fast breeder reactors (https://en.wikipedia.org/wiki/SNR-300 unsucessful due to green opposition) and improved PWRs (https://en.wikipedia.org/wiki/EPR_(nuclear_reactor) co-developed with France, nowadays a few have come online).
The reason why nobody wanted to build them was green opposition. This started before Chernobyl, for example in opposing the Wackersdorf reprocessing plant https://en.wikipedia.org/wiki/Wackersdorf_reprocessing_plant and blocking the refueling operations of existing plants. The green party never got past 10%, but mostly because the parties in government accepted their demands out of fear of strengthening them, because they needed them for a coalition, or because after Chernobyl saying anything positive about nuclear became political suicide. Misinformation was rampant, any German PWR was equated to a Chernobyl in waiting. Experts disagreed and were ignored by media and politicians, shouted down by the greens as industry minions wanting to poison us all.
The reactors shut down under Schroeder were quite profitable, but getting old enough that they would have been switched off soon anyways. Nuclear reactors become more and more profitable over time, because most of the cost is in the initial construction and the financing. After the building is paid off, running cost is quite low, fuel cost is negligible compared to personnel for example. But at some point, repairs, downtime and necessary improvements make it too costly after all. That's when the originally intended replacement should have started, but this was stopped by the Schroeder goverment and the Greens.
And while I don't know whether the Russian influence on and financing of green movements is true or not, it is logical. Russia never had any chance to export its nuclear technology to western countries. Western nuclear power plants were, at least since the 80s, safer and better. The only thing the west could have bought (and actually does still buy) from Russia is uranium. But that is by far a smaller export for Russia than oil and gas. And there are uranium reserves in many western countries, Canada, Australia, the US, Germany and the Czech republic do have large deposits that are only partially exploited, and many other (third-world) countries do have uranium mines and do export (which is why the west is buying there, it's just cheaper). So uranium isn't really a reliable or big business for Russia. Oil and Gas, however, are. And since oil and gas are high-volume goods, imports are far less flexible than uranium imports. Basically, if you want it cheap, you need a pipeline, which is the perfect leash for the Russians to hold. And lo and behold, Schroeder, while making plans to shut down all German nuclear power plants over time, planned to increase gas imports from Russia, which was upheld during the later Merkel years. Schroeder was, after his term, rewarded for this with a position at Russia's state gas producer Gazprom. So it would be in Russia's interest to reduce nuclear power use in Europe and get Europe dependent on their gas.
Btw. the meaning of "green" has changed. Back in the Schroeder days and before, green was largely pro-environment and anti-nuke. But CO₂ emissions and global warming weren't a huge topic. Open-pit coal mining and coal plants were opposed on grounds of landscape destruction, resettlement and pollution. But CO₂ was never the big topic that it is nowadays. Therefore, back in those days, even for the Greens, "clean" gas power plants were a viable replacement.
Schröder was a social democrat and personal friend of Putin. He managed to score a deal and secure his own future..