To rely on variable sources like wind and solar you need a lot of storage - I;d suggest perhaps 2 weeks worth of generation. That is quite a practical volume with coal and oil, less so with electricity I suspect interest in generating gas by electrolysis, storing very cold or very compressed gasses, and other things that are a bit cleverer than just big battery or two.
To rely on variable sources like wind and solar you need a lot of storage - I;d suggest perhaps 2 weeks worth of generation. That is quite a practical volume with coal and oil, less so with electricity I suspect interest in generating gas by electrolysis, storing very cold or very compressed gasses, and other things that are a bit cleverer than just big battery or two.
