California's First Hydroelectric Plant in Six Years

In spring 2001, Metropolitan Water District began generating clean power from new turbine generators brought online at Diamond Valley Lake. These hydroelectric generators are the first hydroelectric units to be brought online in California in six years, according to the California Energy Commission. The facility will ultimately be capable of generating up to 40 megawatts of electricity, enough to power 40,000 households for a year. During this first phase, the facility will produce as much as 13 megawatts of clean power. Hydroelectric power is clean energy because it does not require burning other fuel sources to generate.

An Accelerated Process

The Hiram W. Wadsworth Pumping Plant at Diamond Valley Lake was originally designed as a pumping plant, not a hydroelectric generator. Engineers originally planned to convert the pumps to turbines by summer 2002.

In order to help California through an expected summer of rolling blackouts and power shortages, Metropolitan accelerated its conversion timeline by one year to bring the turbines online. Metropolitan moved quickly to secure the necessary contracts and agreements with the Federal Energy Regulatory Commission, the California Independent Systems Operator (Cal-ISO), and Southern California Edison. Physical conversion of the pumps took a little less than four weeks.

Metropolitan Gives Back to the State

Metropolitan has moved quickly to reduce its electricity usage as well as find ways to generate new electricity for the power-hungry state. Combining its new clean power generation capabilities with its efforts to curtail power usage, Metropolitan is providing about 150 megawatts of power to the state during peak times. The district has agreements with Southern California Edison and Cal-ISO to shut down up to 20 pumps when needed, resulting in a nearly 45 percent reduction in energy use along the Colorado River. Energy conservation measures also are in place throughout the entire district.

As Needed Sales - Contract Rates

Metropolitan will provide the electricity it produces at Diamond Valley Lake to the Cal-ISO grid through the state Department of Water Resources. Metropolitan will sell power at prices as determined by Cal-ISO.

Facts & Figures

• Total number of pumps that can be converted to turbine generators: 12
• Total converted in spring 2001: 4
• Rated capacity of each turbine: more than 3 megawatts
  
• Average amount of power to be generated this summer: approximately 9 megawatts
  
• Total power generation capacity with all turbines online: approximately 40 megawatts
  

Milestones

• Diamond Valley Lake filling began: May 2000
  
• Feasibility of converting pumps to generators studied: summer 2000
  
• Original target date for conversion: summer 2002
  
• Actual date of conversion: May 2001

How It Works

Water from the State Water Project and the Colorado River Aqueduct is pumped into Diamond Valley Lake and then stored for future use, in order to reduce the threat of water shortages during droughts and peak summer needs. When the water is needed to serve Metropolitan's customers, it flows out of the reservoir and into the district's distribution system.

As the water rushes out of the lake and into the system, it generates a tremendous amount of energy. In order to convert this energy into electricity, four of the twelve pumps have been converted to turbine generators.