An $8 billion green energy initiative that would bring large amounts of clean electricity to the Los Angeles area by 2023 is being called “the 21st Century’s Hoover Dam.” The project would require construction of one of America’s largest wind farms in Wyoming, one of the world’s biggest energy storage facilities in Utah, and a 525-mile electric transmission line connecting the two. The proposed project would generate more than twice the amount of electricity produced by the giant 1930s-era hydroelectric dam in Nevada — 9.2 million megawatt-hours per year vs. 3.9 million megawatt-hours.
A key component of the project is a massive underground energy storage facility that would yield 1,200 MW of electricity — equivalent to the output of a large nuclear power plant and enough to serve an estimated 1.2 million L.A.-area homes — and help solve the intermittency issue that plagues renewable energy.
Linking the wind farm to the energy storage facility would enable the wind farm to function similarly to a traditional coal, nuclear or natural gas power plant — capable of reliably delivering large amounts of electricity whenever needed, based on customer demand. The energy storage facility also would reduce the need for L.A.-area utilities to build expensive backup power plants and power lines to serve customers on days when there’s no wind, at night when there’s no sunlight, and during other periods when traditional wind and solar farms are unable to produce electricity.
Four vertical caverns — carved out of an underground salt formation at the site — would store the energy equivalent of 60,000 megawatt-hours of electricity. During periods of low customer demand, the storage facility would use excess electricity from the wind farm to compress and inject high-pressure air into the caverns for storage. During periods of high customer demand, the facility would use the stored, high-pressure compressed air, combined with a small amount of natural gas, to power eight generators that would produce electricity.
Duke-American Transmission would build the $2.6-billion, 525-mile, high-voltage electric transmission line that would transport the Wyoming wind farm’s electricity to the Utah energy storage facility. The transmission line — a shorter alternative to Duke-American Transmission’s previously proposed 850-mile Zephyr transmission project — would traverse Wyoming, Colorado and Utah, with a target in-service date of 2023. A separate, existing 490-mile transmission line — traversing Utah, Nevada and California — would transport electricity from the Utah energy storage facility to the Los Angeles area.
In response to a request for proposals to supply the Los Angeles area with renewable energy and electricity storage Pathfinder Renewable Wind Energy, Magnum Energy, Dresser-Rand and Duke-American Transmission will formally submit their proposal to the Southern California Public Power Authority by early 2015.