Progressive, responsible environmental leadership is paramount to the business of providing water. San Jose Water Company’s (SJWC) long-standing commitment to the environment began in 1866 when it helped reduce the occurrence of waterborne diseases by delivering high-quality water from artesian wells. Today, SJWC is a leading utility in water treatment and water quality protection, building North America’s first full-scale microfiltration plant and developing other improvements to water supply, water quality and delivery.
SJWC employs state-of-the-art technologies, including industrial control systems to monitor and efficiently utilize energy and water resources. On March 14, 2013, SJWC witnessed the factory acceptance test of its newest pressure-reduction turbine-generators conducted at California State University, Fresno’s (CSUF) state-of-the-art hydraulics laboratory. Zeropex, the manufacturer of this new positive-displacement turbine-generator equipment, was responsible for conducting the factory acceptance test for the new energy recovery technology.
Pressure-reduction turbine-generators replace (or bypass) pressure regulating valves. Water passing through the turbine spins the generator to produce electricity and reduces the pressure of the source water to match the operating pressure of the utility’s distribution system. Each turbine-generator is about the size of an automobile.
Upon installation, this new 150-kW facility could generate as much as 950,000 kilowatt-hours (kWh) of electricity annually for the next 40 years, which is equivalent to the annual energy usage of 110 residences. The local electric utility, Pacific Gas and Electric Co. (PG&E), will purchase all of the electricity.
This is SJWC’s third venture into energy recovery and generation. The first endeavor consisted of a 76-kW solar project commissioned in 2007 producing 110,000-kWh/year. The second endeavor was a 112-kW pressure-reduction turbine-generator commissioned in 2011. In 2012, this pair of 56-kW centrifugal turbine-generators recovered 650,000-kWh of electricity. SJWC presented its energy recovery projects at the America Water Works Association’s ACE12 conference.
For both of SJWC’s turbine-generator sites, the Federal Energy Regulatory Commission issued a hydropower license, and the California Energy Commission certified the projects as qualified renewable energy technologies. SJWC secured generous grants and incentives from the federal government, as well as PG&E, which allowed for the cost-effective deployment of these green projects. The California Public Utilities Commission has authorized all three energy recovery pilot projects.
The CSUF operates a modern 8,200-square-foot hydraulics laboratory. This facility is available to any organization in the water supply and irrigation industries. Additional information can be found at www.icwt.net.