A shower on the upper floor of a high rise building can provide magnificent water pressure - a liquid shiatsu massage. A New York City startup has started tapping into that 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, he told writer David Ferris for 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 explained to me 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. Those standard valves also creates waste heat and pressure in the process, Zammataro said.