The numbers suggest their efforts failed and what they should have done was waited for China to start manufacturing solar panels using the returns from heavy investment in fossil fuels.
But regardless; if we don't have any argument that Germany spent a lot of money on wind/solar and weren't getting power out of it then I think serious people would dispute that wind/solar had higher energy returns than coal at the time. It is pretty obvious that coal/oil/gas had better returns. But it has been a busy decade and it is much more plausible now that renewables are competitive. The explosive growth certainly suggests they are.
Current geopolitical events suggest that not only was reducing European reliance on fossil fuels sourced from the Middle East and Russia a good idea, but that they were not nearly aggressive enough in doing so. IIRC, gas heating still receives government subsidies in Germany that heat pumps do not (and have for more than a decade)
The transition away from oil will take a long, long time, and natural gas will be an essential component in renewable strategies for some time to come. But Europe needs to figure out how to reduce that consumption to not much more than what can be provided domestically and via trade with the US for geopolitical reasons.
Any cost comparison that doesn't factor in geopolitical concerns is incomplete.
> I think serious people would dispute that wind/solar had higher energy returns than coal at the time.
This is why I think it's important when stating that renewables have a higher EROI than fossil fuels, to also emphasise that EROI is a stupid metric that doesn't matter at all in reality.
It was only ever popular with doomers and cranks for this reason.
> what they should have done was waited for China to start manufacturing solar panels
...but China started manufacturing solar panels in no small part because Germany started buying them, promoting a virtuous cycle. It might have been a long wait for that cycle to begin of its own accord!
But regardless; if we don't have any argument that Germany spent a lot of money on wind/solar and weren't getting power out of it then I think serious people would dispute that wind/solar had higher energy returns than coal at the time. It is pretty obvious that coal/oil/gas had better returns. But it has been a busy decade and it is much more plausible now that renewables are competitive. The explosive growth certainly suggests they are.