When you think of the East River in New York City, renewable energy probably isn't the first thing that comes to mind. Yet the river, once a cesspool and dumping ground for an occasional body, has found itself at the forefront of the green-energy movement. In September 2012, Trey Taylor, owner of Verdant Power, sank a special three-bladed electric turbine into the waterway that runs along Manhattan's east side. Taylor designed the turbine, which looks like a modern fan attached to a torpedo-shaped body, to generate electricity from the push and pull of the river's rushing currents [source: McGeehan].
By 2017, 30 of those turbines could dot the river, with each unit generating 35 kilowatts of electricity. If successful, the project could provide enough power to fuel hundreds of homes. Made of plastic and layered fiberglass, the East River tidal turbines are one of several technological innovations rocking the hydroelectric world [source: McGeehan].
From one end of the planet to the other, scientists and engineers are working on a variety of concepts — some real, others imagined — that will help make this very ancient power source an even more important modern one. These days, 6 percent of U.S. electricity comes from hydropower (that's 70 percent of the renewable electricity generated in the U.S.) [source: U.S. DOE]. The supply is limitless, although not every area is a good place to build a hydroelectric project.