Storage is the Achilles' heel of sustainable energy: Making electricity available when and where it's needed is half the battle, and batteries generally aren't an efficient solution. Happily, nature has provided a storage and distribution system in the form of ocean waves, which are essentially stored, concentrated wind energy.
And in September, Edinburgh, Scotland–based Pelamis began harvesting energy from the world's first "wave farm," tethered three miles off the coast of Portugal. Pelamis's three 140-meter-long snakelike thingies undulate on the ocean's surface, forcing fluid through hydraulic motors, which in turn drive generators to produce electricity. Twenty-five more of the machines will be added this year, bringing capacity to 21 megawatts of electricity, enough to power 15,000 to 20,000 homes. Pelamis has two UK wave farm projects in the works, one off the coast of Cornwall and one off the coast of Scotland.