Those renewable energy contracts were mostly a scam in my opinion, most of these providers just bought renewable electricity from the stock market when it was cheap and sold it to consumers at a premium, creating zero new renewable capacity in the process. Greenwashing at its finest. And last year when prices for renewables went through the roof due to several unanticipated factors most of them went belly-up and had to "fire" their long-time customers (myself included) because their business models stopped working as they had built zero renewable energy production themselves.

The whole "Energiewende" feels a bit like that: Electricity production was privatized and more than 300 billion € in subsidies went into investors' hands. Now the infrastructure that was created is mostly privately owned and even though renewable energy production currently peaks the prices go through the roof because consumer prices align with the stock market price of electricity and not the cost of production. It really matters how you create renewable energy.