Power Sources

Intermountain Power Agency shifts to role as energy provider, hub

With the decision to retire coal-fired units at its Intermountain Power Project (IPP) a few years ago, Utah’s Intermountain Power Agency (IPA) now considers itself an energy provider and hub, with plans to build natural gas-fired generation and serve as a bridge for the supply of renewable energy.

And a large-scale storage project located adjacent to the IPP that will include several types of storage at utility scale including compressed air energy storage would “really enhance the position that IPA has as an energy hub,” IPA General Manager Dan Eldredge said.

Eldredge discussed IPA’s shift to an energy provider and hub during a July 30 meeting with American Public Power Association staff members at the Association’s offices in Arlington, Va. He was joined at the meeting by several other IPA officials. 

Background on IPA and IPP

IPA, a separate legal entity and a political subdivision of the State of Utah, was organized in June 1977 for the purposes of undertaking and financing a facility to generate electricity -- the IPP.

The membership of IPA consists of 23 Utah municipalities that own electric utilities. All member entities are located within the State of Utah.

The IPP is located in the Great Basin region of western Utah with capacity to generate more than 13 million megawatt hours of energy each year from its two coal-fired units (900 megawatts each). The energy is delivered over the project’s AC and DC transmission systems to the 35 participants in the project that principally serve Utah and Southern California.

Operating continuously since 1986, the IPP’s participants have operations touching six states. Most of the participants (29) are cities and towns that operate their own electric utilities. Those municipalities range in population from 254 in rural Utah to 3.9 million in southern California. There are six municipal purchasers of project power located in California and 23 municipal purchasers in Utah. The project’s six remaining purchasers are Utah rural cooperatives.

The three main components of IPP are located primarily in Utah and California. The generation station is located near Lynndyl, Millard County, Utah. The Southern Transmission System (STS) extends approximately 490 miles from the generation station to Adelanto, California with an alternating current/direct current converter station at each end.

The Northern Transmission System consists of two segments. The first segment, consisting of two parallel 345-kV AC transmission lines, extends approximately 50 miles from the generation station to a switchyard located near Mona, Utah. The second segment, consisting of a single 230-kV AC transmission line, extends approximately 144 miles from the generation station to the Gonder Switchyard located eight miles north of Ely, Nevada.

Project is a great example of regional cooperation: Eldredge

Eldredge said the IPP is a great example of regional cooperation. The project, which focuses solely on wholesale power markets, has been “extraordinary, actually, in terms of regional cooperation,” he said.

“We found out that the Utah purchasers [the municipals and the cooperatives] had other resources that were more competitively priced than what was coming out of the IPP,” Eldredge noted.

In order to keep the project together, a put and call arrangement was developed. Under the arrangement, every six months, the Utah purchasers make a declaration as to whether they will take power or to put the power back to certain of the California purchasers.

The agreement has created a “remarkable energy reserve” for the Utah purchasers, he said.

Eldredge pointed out that Utah is experiencing growth. “There’s a lot of load that’s coming into the state so having this in the back pocket of our Utah municipal utilities has really been beneficial,” he said.

IPA is an energy provider and energy hub

In May 2017, owners of the IPP announced that they would cease electricity generation using coal in 2025.

IPA is pursuing the construction of a natural gas combined cycle power plant, comprised of two 420-MW units. The plant is scheduled to come online by July 2025.

The planned shift to gas generation “has redefined what IPA is,” Eldredge said. “IPA ‘s not a coal supplier,” Eldredge said. “We now see ourselves as an energy provider and an energy hub.”

He said that the transmission systems for the IPP project “are a wonderful conduit that will bring renewable resources down from the Wyoming and Utah area down into Southern California.”

The STS, which is a DC system, has a capacity of 2,400 MW.

With the closing of the two 900-MW coal-fired units at the IPP site, that would free up a lot more capacity on the STS.

“The Californians can reassign the freed-up STS capacity to bring more renewable resources down into the Southern California area,” Eldredge said.

Storage project

Mitsubishi Hitachi Power Systems and Magnum Development in late May launched the Advanced Clean Energy Storage (ACES) project in central Utah. The ACES initiative calls for the development of 1,000 megawatts of 100 percent clean energy storage.

“We don’t know exactly where that’s going to go, but at least it’s a big idea” that would “really enhance the position that IPA has as an energy hub,” Eldredge said.

In a May 30 news release, Magnum Development said that it owns and controls the only known “Gulf Coast” style domal-quality salt formation in the western United States.

With five salt caverns already in operation for liquid fuels storage, Magnum is continuing to develop Compressed Air Energy Storage and renewable hydrogen storage options, it said. “Strategically located adjacent to the Intermountain Power Project, the Magnum site is positioned to integrate seamlessly with the western U.S. power grid utilizing existing infrastructure,” the company said in the news release.

Magnum Development said the ACES initiative will deploy four types of clean energy storage at utility scale. These energy storage technologies include renewable hydrogen, compressed air energy storage, large scale flow batteries and solid oxide fuel cells.

“If you can’t get viable grid storage of energy it’s going to be hard to integrate all the renewable resources into the grid and so having some kind of storage facility that’s grid scale would be a real premium,” Eldredge said.

Magnum Development noted that in many parts of the western United States, there are times of day when demand for electricity is lower than the production of renewable power, which leads to curtailment of renewable generation and negative electricity pricing.

“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 company said.

Hydrogen and natural gas units

Eldredge noted that the use of hydrogen may be a viable alternative to natural gas.

As IPP orders the units for the planned natural gas plant, the specs that are being asked for include how much hydrogen the units will be capable of utilizing as a co-fuel.

Additional details on IPA and IPP are available here.

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