California officials are looking to streamline the development of transmission lines to access more geothermal power, the state's largest baseload source of in-state renewable energy. At least two geothermal projects have been stalled by lack of transmission access to the grid; several more are in the queue waiting for transmission.
"We have been negatively affected in our geothermal development by slow transmission growth. Having transmission lines in place is a significant issue in trying to market a power-purchase agreement," says Steve Larsen, the president of CE Generation LLC, a unit of Mid-American Energy Holdings that is developing a geothermal project called Black Rock in Imperial County, Calif. The three-unit, 150-MW plant has been in development for almost a decade.
In the Imperial Valley alone, where much of California's highest-temperature geothermal reserves are located, the California Independent System Operator has sifted through 500 proposals to identify 27 that could bring a total of 56,787 MW of renewables to the grid.
In some transmission planning areas—such as the Desert Renewable Energy Conservation Plan area, which covers much of the state southeast of Los Angeles—the state commission is seeking to prioritize geothermal siting considerations "so we don't go chasing solar and wind all around the desert," says California Energy Commissioner Karen Douglas in Sacramento.
One major transmission line that will carry renewable energy is the $1.9-billion Sunrise Powerlink project, which runs west into Los Angeles from the southwest desert. Completion is expected this year.
Furthermore, the Imperial Irrigation District is planning transmission upgrades to move out of the valley an additional 750 MW of geothermal power from four developers.
California already has 25 geothermal plants, which in 2010 produced 12,740 GWh of electricity, 4.2% of the state's energy and more than twice as much as wind, its No. 2 renewable resource. Seventeen more plants are in the works.
