Mitsubishi Hitachi Power Systems Ltd. and Magnum Development LLC on May 30 said they intend to develop a 1,000-MW energy storage facility in central Utah that will combine renewable underground and above-ground clean energy technologies at utility scale.
No price tag has been put on the facility, which is being billed as the "world's largest renewable energy storage project" and has won support from Utah Gov. Gary Herbert, a Republican. A spokesman for Magnum said a full 1,000 MW of storage may not be achieved until around 2030.
The broad outlines of the ambitious project call for Magnum to excavate a cavern that would be filled with compressed air. On the surface, compressors would be driven by excess wind and solar power that would push air into the cavern or by electrolyzers that push hydrogen into the cavern where it can be used at a later date.
In many parts of the Western U.S., demand for electricity is lower than the production of renewable power during certain times of the day. That leads to the curtailment of renewable generation and negative electricity pricing, the storage developers noted.
"Continued deployment of renewables will require that excess power be stored for later use. To serve the needs of the entire western United States, many gigawatt-hours of storage capacity are required," the companies said in a joint statement.
The companies cited Carnegie Mellon University data that showed CO2 emissions from the U.S. power sector have dropped 30% since 2005 "because of a combination of natural gas and renewable power replacing retiring coal-fired power plants."
The Advanced Clean Energy Storage, or ACES, initiative will focus on 100% clean energy storage by deploying what the companies call "technologies and strategies essential to a decarbonized future for the power grid of the Western United States." Those energy storage technologies include renewable hydrogen, compressed air energy storage, large scale flow batteries and solid oxide fuel cells.
"The technologies will store electricity on time scales from seconds to seasons of the year," said Paul Browning, president and CEO of Mitsubishi Hitachi Power Systems subsidiary Mitsubishi Hitachi Power Systems Americas Inc., which is headquartered in Lake Mary, Fla. "For example, when we add gas turbines powered with renewable hydrogen to a hydrogen storage salt-dome, we have a solution that stores and generates electricity with zero carbon emissions."
Excess electricity from solar, wind and other renewable energy sources can be used to create renewable hydrogen through electrolysis, splitting hydrogen from oxygen. The resulting hydrogen can then be stored for future use.
The 'next step'
Magnum Development, based in Holladay, Utah, develops salt cavern natural gas storage facilities. The company said it has five salt caverns in operation for liquid fuels storage and is in the process of developing compressed air energy storage and renewable hydrogen storage options.
The ACES project will be situated on a Magnum property adjacent to the Intermountain Power Project — an approximately 1,800-MW, coal-fired facility near Delta, Utah, which is owned by the Intermountain Power Agency and due to shut by 2025. The IPA plans to develop a new natural gas-fired combined cycle facility at the site by that year.
The site for the new storage facility, roughly 135-miles southwest of Salt Lake City, is near existing regional electricity grid connections, fully developed transportation infrastructure, ample solar and wind development capacity, a skilled workforce currently transitioning away from coal, "and, of course, the unique salt dome opportunity," said Craig Broussard, CEO of Magnum.
The ACES partners are expecting to bring in additional partners on the project, which may have 100-MW of storage capacity in place by 2025.
"For 20 years, we've been reducing carbon emissions of the U.S. power grid using natural gas in combination with renewable power to replace retiring coal-fired power generation," Browning said. "In California and other states in the western United States, which will soon have retired all of their coal-fired power generation, we need the next step in decarbonization. Mixing natural gas and storage, and eventually using 100% renewable storage, is that next step."
Jeffrey Ryser is a reporter for S&P Global Platts. S&P Global Platts and S&P Global Market Intelligence are owned by S&P Global Inc.