How to power the world with Wind, Water, and Sun

…a new study just published in the journal Energy Policy states that the world can provide for all of its energy needs, including electric power, transportation, heating/cooling, etc using only wind, water, and solar (WWS) energy by the year 2030.
By water the study authors, Mark Z. Jacobson (pictured) Mark A. Delucch, mostly mean hydroelectric power, which would involve building more dams, with all their environmental problems. Still, it’s an interesting study demonstrating that true renewable energy could power the world: no coal, no oil, no nuclear.