Harnessing the Power of Water on Its Way to Your Tap

Clean energy entrepreneurs in New York City have turned their attention toward an untapped source of power flowing beneath the streets for nearly a century: the water mains. By the time the city's water supply completes the 125-mile trip down from the streams of the Catskill Mountains, it picks up an awful lot of speed, which city officials hope can be used to spin turbines and feed energy into the grid.

"Powered only by gravity, nearly a million gallons of water rushes into the city every minute," Dwyer writers. "From streams dammed in the hills and mountains north of the city, the flow moves with such force that even as it branches into pipes that run down every street, it rises to a height of six stories on pure momentum. Below that, most buildings need no pumps."

Frank Zammataro, president and founder of Rentricity Inc., is spearheading the proposal. "We're not talking about building the Hoover Dam," he points out. As generators would have to be installed right under the pavement, it would either require new infrastructure to carry that energy back to the grid, or be used right on the streets.

Soon, the city will study the feasibility of the proposal, under a bill sponsored by Queens City Council member James F. Gennaro. But critics warn that it may be nothing more than a pipe dream. Dwyer elaborates: "At least one of Mr. Gennaro's estimates about potential power has been about 200 times too high, officials said. Still, he noted that the new study was agreed to by the mayor. It is due in 18 months."