With the coal-fired Intermountain Power Plant in Utah being shuttered next decade for climate change purposes, one of the replacement options being looked at is a 1,200-MW compressed air energy storage (CAES) project at the site.
Robert Schulte of consulting firm Schulte Associates LLC described the project in a Dec. 7 presentation at Pennwell’s GenForum conference in Las Vegas, Nevada. The conference was part of the annual Power Generation Week gathering. Schulte has been doing work in this area on behalf of IPP participant Burbank Water & Power.
Schulte said the idea is to take power from the planned 3,000-MW Pathfinder Renewable Wind Energy project in Wyoming and feed it down the proposed 500-kV Zephyr Transmission line to the current IPP site in Utah. The power could then be used to pump air into underground salt caverns, with that air then released during peak demand periods to generate electricity.
In that respect, CAES is similar to pumped storage hydro, which uses electricity to store a medium that can then be released when needed to generate power. This form of energy storage is considered particularly valuable at a time when highly variable wind and solar output is increasingly dominating the grid.
The CAES would go online in two phases: A 300-MW phase to be commercially operating in 2020; and a 900-MW phase to be commercially operating in 2024.
One reason to do the CAES project is to take advantage of the existing 500-kV power line that takes power from IPP into the California market for offtakers like the Los Angeles Department of Water and Power. The line can handle about 2,400 MW of power, Schulte noted, with the current IPP plant at about 1,900 MW in size. Schulte said the idea is to “take all that wind and pack it down the transmission line” to California.
There are four large salt caverns available at the site that can store enough compressed air for about 48 hours of power generation, Schulte said. The compressed air equipment would be supplied by Dresser-Rand.
The alternative that has been used in the economic models has been a conventional 1,200-MW natural gas combined-cycle plant at the IPP site. An advantage of the CAES project over the gas-fired project is that it is more compatible with integrating renewable energy to the grid, Schulte said.
He noted that there are a lot of issues to be resolved before any CAES project can become a reality. This is a different kind of power generation than the IPP, so it would have to be worked out among IPP participants that are potential customers for the CAES project so each gets equal costs and benefits from the project.
Other speakers at GenForum addressed various issues. Michael Reed of the U.S. Department of Energy said the department has about $40 billion of remaining loan authority for clean energy projects. Past loan support has gone to projects like the new Vogtle nuclear capacity being built by Georgia Power. He noted that DOE money can help push technology development and acceptatance, like the $4.6 billion that went to 1,502 MW of solar projects earlier this decade, which helped spark the recent surge of solar projects being built without DOE money.
Jacob Williams, vice president at Peabody Energy, the nation’s largest coal producer, described how cheap coal-fired power has been and can continue to be a way to pull people around the world out of poverty and into longer, healthier lives. He noted how the air in the U.S. is among the cleanest of any industrialized country in the world, despite what environmental groups claim.
Todd Williams of the consulting firm ScottMadden described the U.S. Environmental Protection Agency’s newly-published Clean Power Plan and how 27 states are now appealing it in federal court.