Southern Utah is renowned for its red sandstone national parks, but the region is quickly becoming a frontier for renewable energy. In a small area, spanning just 140 miles between the towns of Delta and Cedar City, various forms of renewable energy are “co-produced.” This area offers a field-scale analog for the renewable energy revolution.
Hydrogen Storage in a Salt Dome
Delta, located 130 miles south of Salt Lake City, sits atop a Jurassic-age salt dome, which offers the best conditions for underground hydrogen storage. This is what the Advanced Clean Energy Storage Delta or ACES Delta project aims to do. The project started in 2022 with a loan of $504.4 million from the U.S. Department of Energy and is perhaps the largest hydrogen storage project of its kind. Chevron and Mitsubishi Power Americas own and operate ACES Delta.
ACES Delta has already constructed two salt caverns via solution mining – each almost the size of the Empire State Building – roughly 3,500 feet underground and in temperatures around 140-degrees Fahrenheit. Each salt cavern can store 5,500 metric tonnes of compressed hydrogen. With the underground salt dome covering 4,800 acres, the area has the potential for dozens of salt caverns to be constructed.
The ACES Delta facility is a remarkable piece of geoengineering. Above ground, hydrogen is flammable, fugitive and reactive; therefore, the entire hydrogen generation and injection process must be completely sealed. Underground, the salt formation is ductile and flowy. This means hydrogen must be stored alongside a base or cushion gas along (usually methane) at pressures of 1,000 pounds per square inch to prevent shrinkage of the salt caverns.
ACES Delta closely collaborates with the Intermountain Power Agency, a utility company already operating two coal-powered plants and planning to add a natural gas power plant. The IPA will supply high-voltage electricity to ACES Delta for water electrolysis that produces hydrogen. It will also harness the stored hydrogen to fuel gas turbines. Starting in 2025, the fuel will be a blend of 30-percent hydrogen and 70-percent natural gas, but the hydrogen ratio will increase to 100 percent by 2045.
Enhanced Geothermal Systems
Seventy-five miles south of Delta lies Milford in Beaver County, Part of the Great Utah Basin, where many of Utah’s geothermal power plants are located. Unlike the 28-mile-thick continental crust of Colorado Plateau, the crust in the Great Basin is stretched and thinned to 18 miles and sits atop a hot magma chamber. The plants near Milford include three conventional hot-water plants: Blundell or Roosevelt Hot Spring (34 megawatts) owned by PacifiCorp; Thermo Geothermal Plant; and Cove Fort (25 megawatts) owned by Ormat Technologies.
Utah’s cutting-edge geothermal plant is the Frontier Observatory for Research in Geothermal Energy. Funded with $220 million by the DOE and operated by The University of Utah’s Energy & Geoscience Institute, FORGE aims to tap into heat resources in basement granite (“hot dry rock” with temperatures over 500-degrees Fahrenheit) by drilling deviated wells into and fracturing granite. It is a pioneer enhanced geothermal system.
In May, FORGE ran a nine-hour circulation test that validated water communication between the wells with a recover efficiency of 70 percent. This was followed by a 30-day circulation test in August.
Wind and Solar Farms
Solar and wind power now account for 18 percent of Utah’s electricity generation. Adjacent to FORGE is the Milford Wind Corridor, which was built by First Wind in two phases and completed by 2011. Phase 1 began in 2008 and has a posted capacity of 204 megawatts with 97 wind turbines, and Phase 2 included an additional 68 turbines with a total capacity of 102 megawatts. Milford Wind is owned by Longroad Energy.
Utah’s greatest growth has been in solar power. In 2016, SunEdison and Dominion built the Escalante, Enterprise and Three Cedars solar farms, now owned by Clearway Energy. Escalante Solar farm is adjacent to Milford Wind farm and consists of three 80-megawatt photovoltaic units. Enterprise solar farm with 80-megawatt capacity is located near Cedar City, some 60 miles to the south of Escalante solar farm. Three Cedars Solar project consists of three units to the west of Cedar City with a combined power capacity of 190 megawatts.
Why the concentration of renewable energy developments in the Great Basin? The bedrock geothermal gradient in the Great Basin is about 40-degrees Celsius per kilometer, and its geographic position and elevation mean it often receives solar radiation of about 6 kilowatt hours per square meter per day. Finally, California’s high demand for electricity also provides economic incentive for Utah’s New Energy Corridor.
Southern Utah offers a look at the distant geologic past – the Jurassic age – but also a glimpse into the energy transition of the future. We see Utah projects already impacting the tech sector: In 2023, Fervo Energy launched a 400-megawatt EGS plant called Cape Station near the FORGE site. Part of the electricity produced by Fervo will be supplied to Google. And new energy in Utah still has a lot of potential to grow.