The Key to Running the World on Solar and Wind Power

Perhaps the biggest shortcoming of solar and wind power is their intermittency. In locations like Hawaii, where I live, wind and solar power are already competitive on price. My fossil-fuel supplied electricity typically costs above 40 cents a kilowatt-hour, and wind and solar power can compete with that. But since they can’t supply power that is available on demand (firm power) they must be backed up by power sources that can provide power when the sun isn’t shining and the wind isn’t blowing.