There are few more important questions for the 21st century than how we will power our electric grids. Literally trillions of dollars and are at stake, and possibly even the future of the planet. It’s a good bet that wind and solar will make up the majority of the future grid. But, wind and solar are not the same. Wind turbines benefit from economies of scale. As they get bigger, their costs go down; but only up to a point. By comparison, solar’s cost declines are driven by something even more powerful, economies of volume – the more you make of something, the cheaper it gets.