There's plenty of R&D into cloudy-day solar collection, and there's also wind, tidal, hydro, as well as many clean battery technologies ranging from chemical to

There's plenty of R&D into cloudy-day solar collection, and there's also wind, tidal, hydro, as well as many clean battery technologies ranging from chemical to heat to gravitational. Not to mention traditional backup systems and smart grids. We're not so fragile that cloudy days will shut down our energy grid.