Water plant goes with flow to reduce electricity costs

| Saturday, Oct. 2, 2010

The pumps that pull water from Beaver Run Reservoir and send it to a water treatment plant are now being powered in part by the very water that flows through them.

The Municipal Authority of Westmoreland County is using the first energy-recovery system installed in a water distribution system in the state. The Beaver Run Energy Recovery Project is the first commercial application in the country of such technology by the company that engineered the system, Rentricity Inc.

"As a first, this has been very important to us and very important to our company," Rentricity co-founder Al Spinnell said Friday morning at the Bell Township facility.

The $323,000 system installed this summer produces 30 kilowatts of electricity to help power the Beaver Run pump station, which is part of the George R. Sweeney Water Treatment Plant.

Most of the cost was covered by a $232,500 state Department of Environmental Protection Energy Harvest Grant.

John Ashton, assistant manager of operations for MAWC, estimates it will save $40,000 in electricity costs per year.

Several years ago, authority Manager Chris Kerr was looking for ways to save money. "Since electricity accounts for one-third of our production budget, Chris felt this was an area we must get under control," Ashton said.

Through research into electricity conservation, authority officials came across Rentricity, a New York City-based company founded in 2003 to explore ways to recover energy in water pipes.

Rentricity, which operates a Pittsburgh office, uses existing technology to produce electricity from water systems. Its first endeavor was a pilot program in Connecticut that recovers electricity from pressure reduction valves, which bring down the pressure inside a water system's distribution lines to allow it to safely flow into homes and businesses.

The system draws energy from some of the 6.8 million gallons of water MAWC releases daily from the reservoir into Beaver Run so the stream can continue flowing.

"The energy of water being discharged was actually energy that was being wasted," Ashton said.

Water from the pump station flows into a turbine, which then turns a blade. Once that blade hits a certain speed, an attached generator begins to produce power that flows through conduit back to the pump station.

About 5.4 million gallons flows through the turbine and back into the stream. Another 1.4 million gallons flows through a bypass around the turbine and directly into the stream. If the turbine ever needs to be shut down for repairs, all the water could flow through the bypass.

Rentricity's Frank Bursic, who managed the Beaver Run project, said a turbine could have been designed and built to handle all 6.8 million gallons, but his company uses existing equipment and retrofits it for their needs. The turbine they are using is a standard size rather than a custom design, saving money.

"We can drive the cost down because we can use existing technology," Bursic said.

Rentricity is working on projects in New Hampshire and California. MAWC officials are looking at other locations where they can use the technology, including the Indian Creek water treatment facility in Fayette County and within distribution lines, Ashton said.

"As a water supplier, we are looking at the environment and what we can do to protect it," Ashton added.

Subscribe today! Click here for our subscription offers.


Show commenting policy