[NeilBlanchard]

A range of different renewable energy sources that are spread out geographically can provide plenty of energy - as much as SIXTEEN TIMES as much as we currently use.
With that much energy available, we could get by with very little storage.

Solar PV works right at the peak demand for A/C. Wind blows more at night, and waves are continuous is some parts of the ocean, and the tides are huge in some areas, and geothermal is easily available in some areas.

We can store methane gas that comes from digesters, that use either sewage or farm waste. Solar heat systems can store molten salt underground for days. Grid storage batteries are happening right now. Flywheel and compressed air (stored underground) and elevated reservoirs are known technologies.