DieterHH,

The predicted ten fold increase in solar power that you mention may well be an underestimate. In a number of countries solar energy projects are now producing power at a cost below 3 cents per kWh. The cost for storage is lower again in many cases and, of course, one need not store all of the power.

http://tucson.com/business/tucson/tucson-tech-ua-solar-zone-enters-second-phase/article_d720a953-4610-50b2-867f-9a41fdc6c927.html

http://www.washingtonpost.com/sf/world/2017/03/31/while-trump-promotes-coal-other-countries-are-turning-to-cheap-sun-power/?utm_term=.8dc8126efd68

Most of the new electrical generation capacity worldwide last year was renewable. That may not change. Natural gas generation will of course be important for decades to come.

https://www.forbes.com/sites/mclifford/2016/06/29/cheaper-than-coal-dubai-to-build-worlds-lowest-cost-solar-plant/#57d5d9b51c81