The State Water Project (SWP) is one of the largest electricity users in California. From the Delta through the San Joaquin Valley to Southern California reservoirs, the SWP uses electricity to lift water to elevations as high as 1,926 feet before gravity furthers its conveyance from north to south.
There are 23 pumping plants in the SWP, which means that the system requires a dependable, economical power source to make its water deliveries. To provide some of that power, DWR constructed a system of power and power recovery plants as part of the SWP. Energy needed to operate SWP pumps also comes from energy exchanged and purchased from other utilities.
Nine hydroelectric power generation plants produce much of the energy needed to move SWP water to areas of need in California. The energy produced—which is highly variable due to changes in annual hydrologic conditions—averages around 6 billion kilowatt-hours (kWh) a year. As a producer of electricity, we are subject to regulation under the authority of the Federal Power Act. We have three hydropower licenses and two conduit exemptions under authority of the Federal Energy Regulatory Commission. To maintain these licenses, we must comply with the terms and conditions to protect, mitigate and enhance beneficial public uses of hydropower projects.
The SWP’s flexible pumping operations help it to manage its power needs. This flexibility is allowed by Project reservoirs, which temporarily store water until it is needed to meet the daily and seasonal demands of its contracting agencies.
To reduce power costs, pumping is minimized during on-peak hours when power prices are highest. Maximum pumping is scheduled during off-peak periods (nights, weekends and holidays) when power costs are cheaper. Thus the SWP can purchase, when needed, inexpensive surplus generation from other power suppliers for its pumping operations.
The Project also can sell surplus power when its power needs are less than its resources. The revenue from these sales helps keep the net cost of water deliveries more affordable.