Water District Invests in Clean Power Generation

Chuck Colgan's picture

Residents in a large section of San Diego North County are now drinking water treated by 100% clean energy thanks to an innovative power system recently installed by the Olivenhain Municipal Water District (OMWD) that transforms water pressure into electricity.

The water district is using a turbine technology that generates power from the reduction in pressure in water pipelines to convert mechanical energy into electrical energy. The system cost about $2.2 million, however, they saved $625,000, or nearly 30%, through a rebate from the statewide Self-Generation Incentive Program (SGIP) administered by CCSE in the San Diego Gas & Electric service territory.

"The pressure reduction turbines are one of several projects the district has implemented that have resulted in 100% renewable power for all of our facilities,” said Tom Kennedy, OMWD operations manager. “We have the lowest carbon footprint of any water district in San Diego County."

The district expects the two turbines, with an average output of 500 kilowatts, to reduce their greenhouse gas emissions by more than 1,390 tons of CO2 annually, equivalent to removing about 290 cars from the road.

How it Works

The water district installed two pressure reduction turbines at its David C. McCollom Water Treatment Plant in Escondido that provide electricity to power half of the facility’s on-site energy needs, saving the district more than $500,000 a year in energy costs. The OMWD plant filters up to 34 million gallons of water daily, distributing clean, potable water to some 80,000 people in San Diego North County.

Pressure reduction turbines generate power from the reduction in pressure in water and natural gas pipelines or steam systems. The water, natural gas or steam is directed through valves that press against the blades of a turbine, which powers an electric generator. At the OMWD facility, the majority of the electricity generated goes toward powering the pumps used to treat and deliver the water.

Rebates for Efficient Technologies

Since 2001, CCSE’s SGIP team has issued more than $53 million in incentives and approved nearly 35 megawatts of on-site generation capacity in the San Diego region for projects using wind turbines, pressure reduction turbines, internal combustion engines, microturbines, gas turbines, advanced energy storage and fuel cells.

To learn more about pressure reduction turbines and other SGIP-incentivized technologies, visit the Self-Generation Incentive Program.

Chuck Colgan