Key numbers
About the San Gabriel Valley Water Company
San Gabriel Valley Water Company (SGVWC) is a California-based public water utility headquartered in El Monte, CA that provides safe, clean and reliable drinking water to multiple communities throughout the Los Angeles region. The Sandhill WTP (overhead picture right) is one of SGVWC’s drinking water plants, which takes raw imported water, treats it, and distributes it to households in the Rialto, CA area.
Sandhill WTP’s water supply is gravity-fed from higher elevations, creating 115 to 150 pounds per square inch (psi) of pressure upstream of the treatment plant. This pressure has to be regulated and reduced prior to the plant to avoid damaging the piping and water treatment system. The embedded energy in this water is lost entirely to noise and heat as the pressure reducing valves (PRVs) burn through the pressure. Simultaneously, Sandhill WTP’s largest operating cost besides personnel is the electricity to operate the treatment and distribution technologies at the plant.
Case study participants
In-Conduit Hydropower
NLine Energy, Inc. the Associate of California Water Agency’s approved provider for small hydropower services was hired to develop an in-conduit, hydroelectric, energy recovery facility for Sandhill WTP. NLine Energy identified that the energy dissipated at the existing PRV could be converted into AB 32-certified renewable energy through the use of a micro-hydropower turbine technology. By installing dual-turbine array of pumps-as-turbine powerhouse (pictured right), SGVWC is able to turn a water treatment plant into a 310 kW renewable energy generator.
generate sufficient energy to turn the WTP net energy neutral. The electricity generated is then fed to the nearby Southern California Edison electric grid, through a net-energy metering agreement
Performance and Economics
Since the site was commissioned in November 2013, the Sandhill WTP has achieved net-energy neutrality, generating more electricity than it requires to operate. To date, the site has generated nearly 2 million kilowatt hours of clean, renewable electricity, the equivalent of 1,300 tons of CO2 saved.
| Sandhill WTP Hydroelectric Station | |
| Owner | San Gabriel Valley Water Company |
| Developer | NLine Energy, Inc. |
| Location | Rialto, CA |
| Turbine | Pump-as-Turbines |
| Turbine(s) rating | 310 kW |
| Cost | $1,675,000 |
| Payback | 8 years |
Conclusion
SGVWC has been able to harness the wasted energy embedded within its existing water infrastructure to create a new source of distributed renewable electricity. This novel configuration of tried-and-true turbine technologies is operationally benign, low-maintenance, and cost-effective.
Andrew Benjamin, NLine Project Manager
Are you sitting on a source of wasted energy? Would you like to convert this into clean, renewable power? Give us a call! You’ll get a free assessment with an expert who can instantly identify your opportunity.
Are you sitting on a source of wasted energy? Would you like to convert this into clean, renewable power? Give us a call! You’ll get a free assessment with an expert who can instantly identify your opportunity.
Andrew Benjamin, NLine Project Manager
