In Utah, hydrogen and salt domes are winning the west for renewable energy

Remember the excitement about hydrogen early this century? The lightest element on the periodic table was touted as a cure-all for energy needs in everything from portable devices to high rises.

Mike Ducker remembers. He was an engineer for the U.S. Department of Energy at the time, and part of his job was to evaluate the potential of energy solutions such as hydrogen.

"There was a lot of buzz, but clearly that fizzled out," Ducker says. "Fifteen years later, the dynamics are fundamentally different. Just in the past year, there's been overwhelming interest in storing renewable power, particularly in the western United States where curtailment of renewable power generation is now a routine occurrence."

Last December, Ducker and his family were living in Pittsburgh, where he was senior director of New Product Solutions & Operations for Mitsubishi Power, part of Mitsubishi Heavy Industries (MHI) Group.

One day, he got a call from Mitsubishi Power Americas president and CEO Paul Browning. Things were moving on the hydrogen front. California was aggressively pushing to decarbonize its energy supply, and Mitsubishi Power, in partnership with Utah-based Magnum Development, was to play a key role in developing a hydrogen-based renewable energy storage complex that could enable continued decarbonization of the West. The project, known as Advanced Clean Energy Storage, will be the first utility-scale renewable hydrogen creation, storage and transmission project.

Advanced Clean Energy Storage needed a knowledgeable leader who could take hydrogen storage into the mainstream. Are you interested? Browning asked Ducker. The answer came quickly.

"Within four weeks, we had our bags packed and we set off across the country with our two young children and puppy from Pittsburgh to Salt Lake City," says Ducker, who became the new vice president, Renewable Fuels & Western Region, for Mitsubishi Power. "I would not move my entire family 2,000 miles across the country if I didn't truly believe this is the right timing and has the potential to do what we hoped for [with hydrogen] 15 years ago."

A Salt Dome Solution

The three biggest challenges in using hydrogen to store clean energy are converting renewable electricity to hydrogen affordably, storing large amounts of hydrogen for long periods of time at low cost, and converting the hydrogen back to electricity at low cost and high efficiency.

Ducker knew that his colleagues at Mitsubishi Power had a development program to use hydrogen as a fuel in their largest and most efficient gas turbine. He also knew that the electrolysis products to convert electricity to hydrogen existed and could be cost reduced through improved economies of scale.

Hydrogen storage at substantial and affordable scale however, had been a real barrier.

Enter the salt dome beneath Delta, Utah. Salt domes are underground salt formations, huge saline globes that intrude into other strata of the earth. Given salt's impermeability, they can be hollowed out and used as underground storage for liquid and gas fuels.

Browning was discussing hydrogen storage with a large customer of Mitsubishi Power who recognized that the Delta dome was a viable candidate for hydrogen storage in the western U.S. and gave Browning the contact information of the Magnum development team. Browning discussed this with Dave Hunt, Mitsubishi Power senior vice president for North America, who earlier in his career had worked in the hydrogen industry. A "light bulb went off at Mitsubishi Power," says Ducker, "and Hunt worked quickly laying out the details of the hydrogen strategy and creating the partnership with Magnum."

Now, Mitsubishi Power and Magnum are co-developing the Delta salt dome for hydrogen storage.

Creating a storage cavern at Delta involves a sophisticated subterranean engineering process. Water is injected into a dome, creating a brine solution that is then pumped out. The resulting caverns are cylindrical and typically between 150 and 300 feet in diameter and 1,000 and 1,500 feet deep. A single cavern can contain enough pressurized hydrogen to produce 150,000 megawatt-hours of energy. You would need 40,000 shipping containers of lithium-ion batteries for the same megawatt-hours.

This kind of underground hydrogen storage is a proven technology. In Texas, salt caverns have been used to store hydrogen produced from natural gas since the 1980s. However, Advanced Clean Energy Storage will represent the first utility-scale implementation of renewable hydrogen for energy storage, industrial and transportation applications.

The huge salt dome in Delta, Utah could potentially house as many as 100 storage caverns.

Hydrogen In The Bigger Picture

The significance of Advanced Clean Energy Storage stems from the fact that an increasing percentage of renewable energy goes to waste for lack of an adequate storage solution. While battery storage has become increasingly affordable for short duration of time (a few hours), storage is also needed on a seasonal basis in the American West. In the spring, the combination of lower temperatures, copious sunlight, strong winds and snowmelt leads to large energy surpluses that go unused, or "curtailed" in industry parlance, to the tune of hundreds of thousands of megawatt hours.

Hydrogen could go from being wishful thinking to an essential part of California's push to reach 100 percent zero-carbon electricity.

In the near future, that energy will generate hydrogen through electrolysis. The resulting hydrogen will be stored in the Advanced Clean Energy Storage salt cavern, and then tapped in periods of higher energy demand. "One of our caverns has the capacity to store the entire state of California's monthly curtailed energy," Ducker says.

Customers are investing in technology that is hydrogen capable. For example, Intermountain Power Agency (IPA) will retire its coal units at the Intermountain Power Plant (IPP) in 2025. They will replace them with Mitsubishi Power's highly efficient gas turbine combined cycle technology that will initially be capable of utilizing 30% renewable hydrogen as a clean energy fuel, and will reach 100% renewable hydrogen capability no later than 2045. This plant will supply stored renewable power to the Los Angeles basin and other power users throughout California and Utah.

In just a few years, hydrogen could go from being wishful thinking to an essential part of California's push to reach 100 percent zero-carbon electricity by 2045.

"If State Governments and utilities are going to achieve aggressive decarbonization targets in the coming years, long duration renewable power storage using hydrogen has to be part of the answer," Ducker says. "This is truly a change in power."