1,200 MW energy storage project proposed in Utah to support wind power

Four companies have jointly proposed an $8-billion green energy initiative that would link wind farms to an energy storage facility and bring large amounts of clean electricity to the Los Angeles area by 2023. 

The project would require construction of a wind farm in Wyoming, an energy storage facility in Utah, and a 525-mile electric transmission line connecting the two sites. A key component of the project – a massive underground energy storage facility – would yield 1,200 MW.

The four companies – 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 in response to the agency's request for proposals to supply the Los Angeles area with renewable energy and electricity storage.

The underground energy storage facility would help solve one of renewable energy's biggest challenges – its intermittency. Wind farms produce no electricity when there's no wind; solar farms produce no electricity when there's no sun.

Linking the wind farm to the energy storage facility is likely to enable the wind farm to function like a traditional coal, nuclear or natural gas power plant – capable of reliably delivering large amounts of electricity whenever needed, based on customer demand.

Key components of the proposed project:

• Wind farm - Pathfinder Renewable Wind Energy would build, own and operate the $4-billion wind farm - near Chugwater, Wyo., 40 miles north of Cheyenne - which would generate 2,100 MW of electricity.
• Energy storage facility - Pathfinder Renewable Wind Energy, Magnum Energy and Dresser-Rand would install the $1.5-billion "compressed air energy storage" system at a site near Delta, Utah, 130 miles southwest of Salt Lake City. Four vertical caverns - carved out of an underground salt formation at the site - would be key components of the storage system. 
• Each cavern would be about a quarter-mile in height, 290 feet in diameter and 41 million cubic feet in volume. The four caverns combined would store the energy equivalent of 60,000 MW-hours of electricity. During periods of low customer demand, the storage facility would use excess electricity from the Pathfinder 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.
• Electric transmission line - Duke-American Transmission proposes to 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.