I don't know of it was NIMBYism, but a few years ago the relatively simple feed in tariff system was replaced by a kind of a bidding system designed to allow new capacity addition to the most efficient producer. But by design they tried to limit the amount of new capacity added. Honestly I don't know all the details, but it's not very far fetched that there was a fair bit of politics involved, and protection of interests of a lot of non renewable energy producers.

Some details here https://m.dw.com/en/german-cabinet-puts-brakes-on-clean-ener...