Ha, yes, a lot of deniers/delayers are going on about how Germany "wasted" billion on renewables, when in fact they had a booming solar industry, which got nuked by politicians, who changed the policies, as can be seen in 39C3 video "Recharge your batteries with us".

Was the subsidy system which was in effect in 2010's unsustainable? I think so, yeah. But the changed policies resulted in companies producing solar going bust, and the Chinese firms, which were doing fine, were able to buy out the patents and know how.

So, did Germany waste billions? Yes, but by letting the solar producers go bust.

Solar panel production is extremely energy intensive. Germany has one of the highest energy costs in the world. So there was no way for Germany to maintain a competitive solar panel industry.