Do you have any idea the cost of a solar and wind turbine system is just to support say 10K Watts of power supplies is? Do you know how much land/roof area you need to support 10kw worth of panels? False economy!
At least I know some approximate numbers 
In Germany, for example, there are a few solar parks generating electricity for about 4 cents per kilowatt/hour (most are generating at 6-8 cent, however). We're talking about a country with a relatively cloudy climate. In Mexico and Chile, solar power plants are being built with the operators guaranteeing prices of ~2 cent per kilowatt-hour. They're expected to get connected to the grid in the early 2020s (I think it was 2021).
So no, massive solar mining is not as far away as you may think.