Wave energy is more evenly distributed across the globe than tidal currents, but it's also more violent: Generators floating on the surface of the ocean must function while being thrashed around. London-based 40South Energy built a wave-energy converter that cleverly avoids abuse. It remains submerged in the water column, automatically adjusting its depth to find optimal conditions and dodge rough storms. The machine generates energy as its top half, attached to a suspended platform, pulls against the bottom half, moored to the seafloor. 40South plans to deploy its first commercial unit, the 150-kilowatt R115, near Tuscany, Italy, this summer. It's also developing a 2-megawatt version and setting up pilot wave-energy parks in India, Italy, and the U.K.