Power

The SWP is the State's fourth largest generator of electricity and the single largest user of power. How much energy is consumed by Project facilities depends on contractor requests for water and the amount of water available for delivery and storage. Since 1984 power requirements have ranged from under 4 billion to over 8 billion kWh.
Eight hydroelectric plants -- three of which can also pump water-- plus a coal fired facility (DWR owns 67.8 percent of one unit) near Las Vegas, Nevada provide about two-thirds of the Project's power demands. Hyatt Powerplant, combined with Thermalito Diversion Dam Powerplant and Thermalito Pumping-Generating Plant, produce more than 2.4 billion kilowatthours during a median water year. Other power recovery plants--Gianelli (a pumping-generating plant shared with the U.S. Bureau of Reclamation), Alamo, Devil Canyon, Warne, and Mojave Siphon--add to DWR's resources, making it about 5.9 billion kWh.
The rest of the Project's needs are met through a power exchange with Southern California Edison Company, and long and short-term purchases and agreements with other utilities, energy brokers, and power pools. Those include purchases from L.A. Department of Water and Power's Castaic Power Plant on the West Branch (constructed under an agreement between DWR and the Los Angeles Department of Water and Power, but owned and operated by LADWP)) and King River Conservation District's Pine Flat Powerplant.

DWR manages its loads (needs) and resources (generated power) through an extensive computerized network by whichcomputerized network by which operators can remotely control pumping units in its major plants. The SWP's flexibility in managing its pumping operations helps keep its costs down. Much of the pumping is done at night, or off peak hours, when electrical costs are cheap. During daylight, or on-peak, hours, the Project generates power to sell at higher prices.

When power resources are greater than SWP loads, the Department sells surplus power to help defray the net cost of water deliveries to its contracting agencies.
Deregulation of California's electrical industry in 1998 changed the way DWR and major utilities exchanged and sold power. When DWR joined the Independent Services Operator, an entity created to monitor and control the transmission of power over the State power grid, new opportunities were created for marketing power. These included the selling of ancillary services (power that’s there when you need it) in an open market with the potential to sell power at higher prices to offset SWP water delivery costs.