San Diego Gas & Electric (SDG&E) has completed two additional utility-owned energy storage facilities totaling 171 MW, enough to power almost 130,000 homes for four hours.
The 131 MW Westside Canal project located in Imperial Valley – home to a high concentration of solar, wind and geothermal generation facilities – is the largest storage asset in SDG&E’s energy storage portfolio; the 40 MW Fallbrook project, located in Northern San Diego County, is the second largest in its portfolio.
By the end of this year, SDG&E’s energy storage portfolio is expected to reach 345 MW of power capacity, sufficient to meet over 15% of its customers’ load on a typical day and 7% on a system peak day. These energy storage assets participate in the energy markets managed by the California Independent System Operator (CAISO), allowing CAISO to store and dispatch clean energy from the facilities to meet electricity demand as needed.
“The beauty of energy storage is it can help California solve two problems simultaneously: It can soak up surplus renewable energy during the day, so solar and wind farms don’t have to cut off production when demand on the grid is low,” says Miguel Romero, SDG&E vice president of energy innovation.
In recent years, as wind and solar generation capacity has soared in California, renewable generation facilities have had to increasingly curtail, or scale back, energy production to keep the grid balanced. At times, California has had to pay neighboring states to take its oversupply of solar energy in order to avoid overloading the grid.
California has also experienced repeated grid emergencies during record heat waves, which pushed the grid to the brink due to energy demand exceeding supply.
The Westside Canal storage facility consists of more than 800 cubes of stacked lithium-ion batteries that stretch across roughly 16 acres of land. It began commercial operation in June. The Fallbrook energy storage project is also made up of stacks of lithium-ion batteries tightly packed inside metal cubes. It began commercial operation in May. Both facilities are equipped with safety features, remote monitoring and automation technologies. When smoke or other anomalies are detected, the units will automatically shut down.
The completion of these projects follows two other utility-owned storage projects SDG&E has brought online in recent years: the Top Gun Energy Storage Facility (30 MW) in San Diego’s Miramar area and the Kearny Energy Storage Facility (20 MW) in the Kearny Mesa area.