"How does solar energy work when there's no sun?" has been a question for pretty much about as long as solar energy has been a thing.

Of course people wouldn't want solar panels on their houses if installing them meant that, come sunset, the movie they were watching suddenly shut off, forcing them to read by candlelight like colonial settlers. Making solar power a viable option, even when the sun sets or disappears behind some clouds, was one of the first things scientists and engineers had to figure out.

Photo by Andreas Rentz/Getty Images.

Keep Reading Show less
Heroes