It was the conservative CDU with the economic liberal FDP which decided in 2011 to stop using nuclear power in Germany.

At the time when the Greens were in power a decade later, it was already way to late to build out nuclear infrastructure again (not to mention the lack of fuel).

So yes, you've metioned a conspiracy theory without any substance.

The Greens continually pushed for renewables, which the (conservative) government largely ignored in favour of building gas pipelines to Russia.