To quote the Wikipedia article you cited: > This demand can be met by unvarying power plants,[2] dispatchable generation,[3] or by a collection of smaller inte

To quote the Wikipedia article you cited: > This demand can be met by unvarying power plants,[2] dispatchable generation,[3] or by a collection of smaller intermittent energy sources,[4] depending on which approach has the best mix of cost, availability and reliability in any particular market. Renewables are baseload. They mainly compete with other traditional "base load" power plants, i.e. coal and nuclear, all of which rely on dispatch able generation for evening out the peaks and trowths. Your calculation also doesn't make sense, you never need storage to cover the whole electricity generation in all of the US. It's like saying in an all nuclear scenario we need to build plants to cover twice the peak demand because all plants could be under maintenance at the same time. You don't build with 100% redundancy.