We know that an estimated two billion euros was invested in solar last year in Germany. Now, Germany's Solar Industry Association (BSW) has calculated, based on figures from EuPD, that the sector actually generates three billion euros in tax revenue for the state. In other words, solar is actually already a net contributor.
I am in no position to judge whether these figures are accurate. I know that if I heard such a thing from the coal industry, I would be skeptical. But I have also learned that German experts do their math quite carefully, so you really have to be an economist to crack the nut. (Unlike some of the nonsense I am used to seeing elsewhere, which contains bare-faced lies that even I can deconstruct.)