I saw this graph recently, "Fossil fuels have made up at least 80% of U.S. fuel mix since 1900," from eia.gov.
Before 1850 wood generated all of the energy consumed in the US. Since then 80% from coal, gas and oil. I don't think it's coincidence the greatest reduction in poverty, and the greatest increase in human prosperity also took place since 1850.
The chart shows all energy consumption, not just for electricity, which is why the share of coal is so low and the share of oil so high. In any case it shows, in my mind, just how unrealistic it is to think of an economy powered by renewables any time soon.