From a new interview, Bill Gates on the multiple energy miracles that we need:
TR: Then what kinds of energy miracles do we need?
BG: Almost everything called renewable energy is intermittent. I have another term for it: "energy farming." In fact, you need not just a storage miracle, you need a transmission miracle, because intermittent sources are not available in an efficient form in all locations. Now, energy factories, which are hydrocarbon and nuclear energy–those things are nice. You can put a roof on them if you get bad weather. But energy farming? Good luck to you! Unfortunately, conventional energy factories emit CO2 and that is a very tough problem to solve, and there’s a huge disincentive to do research on it.