Water pressure 'tapped' to generate electricity

Birmingham Star (ANI) Wednesday 8th February, 2012

A New York City startup has started tapping into the intense water pressure at treatment plants, reservoirs and factories, converting the excess into electricity.

The idea for the startup, Rentricity, began following 9/11, when president and co-founder Frank Zammataro had to relocate to a conference room that overlooked a rooftop water tower.

Zammataro, who had specialized in information technology for Merrill Lynch, saw opportunity in the towers that maintain water pressure in tall buildings, Discovery News reported.

According to quoted him as telling Ecomagination.com, when water utilities create reservoirs at a high elevation to serve populations living in lower-lying cities, they install pipes for the water to flow down hill.

Zammataro said that the water's speed increases so much while flowing downhill that it has to be slowed down to prevent it from exploding when a customer turns on the faucet.

Utilities reduce that serious water pressure using a specialized valve. Installed in the pipe, the valve dissipates the pressure and slows the flow by squeezing the water column.

Zammataro said that those standard valves also creates waste heat and pressure in the process.

Rentricity makes a turbine-generator device called "Flow-to-Wire," that's basically a wheel connected to a shaft and generator. Water pressure gets dissipated and the flow is slowed, but as the water moves through the wheel, a generator creates an electric field.

"The concept and the technology is quite simple," Zammataro said.

Rentricity installed its technology, which it says is made affordably using off-the-shelf parts, at a water treatment plant in Keene, New Hampshire. The public works director said that the move has cut the plant's energy bill in half. (ANI)