Advocates of generating electricity mostly with intermittent wind and sun, when challenged on how they would deal with a calm night, are always ready with the obvious answer: energy storage. Just get some batteries, store up excess power from the windy mid-days, discharge as needed, and everything will work out. Unfortunately, the advocates never acknowledge that the problem of making an electrical grid work 24/7/365 with mostly wind and solar generation is much more difficult than just storing