Intermountain Power Plant

Intermountain Power Plant
Name	Intermountain Power Plant
Country	United States
Location	Millard County, Utah
Status	Operational/Transitioning
Commissioned	1986
Owner	Intermountain Power Agency
Operator	Los Angeles Department of Water and Power (historic)/Intermountain Power Agency
Primary fuel	Natural gas (conversion from coal)
Secondary fuel	Coal (historic)
Units	2 × 950 MW (steam turbines; historic), planned 840 MW combined-cycle gas
Capacity	1,800 MW (historic)
Coordinates	39°27′N 112°48′W

Intermountain Power Plant is a large thermal power station located in Millard County, Utah, built to supply electricity to municipal utilities and large public agencies. The plant was developed by the Intermountain Power Agency to serve purchaser-members including the Los Angeles Department of Water and Power and several California public utilities. Its remote siting, tall exhaust stacks, and long high-voltage transmission corridor to the Los Angeles Department of Water and Power service area made it a notable piece of regional infrastructure during the late 20th and early 21st centuries.

History

Construction began after agreements among Western public agencies and power authorities in the 1970s and 1980s involving entities such as the Intermountain Power Agency, the Los Angeles Department of Water and Power, the City of Anaheim Public Utilities, the City of Glendale Water and Power, and the City of Burbank Water and Power. The plant was commissioned in 1986 during a period of expanding capacity in the Bonneville Power Administration-era West and aligned with federal and state energy planning involving agencies like the U.S. Department of Energy and regulators in Utah Public Service Commission jurisdictions. Over decades the facility intersected with issues raised by environmental organizations such as the Sierra Club and policy shifts driven by legislation including California Global Warming Solutions Act of 2006 and regional accords like the Western Climate Initiative.

Design and Equipment

The site incorporates two large coal-fired steam turbine units with boilers supplied by manufacturers tied to global suppliers; original equipment procurement involved companies active in the international power market, comparable names include General Electric, Siemens, and Mitsubishi Heavy Industries in utility-scale projects of the era. The plant’s 500-foot exhaust stacks were designed for plume dispersion standards considered in guidance from agencies such as the Environmental Protection Agency and influenced by models used by the National Oceanic and Atmospheric Administration. High-voltage transmission architecture includes series capacitors and long-distance alternating current lines that connect to the Path 27 corridor and tie into substations operated by the Los Angeles Department of Water and Power and regional balancing authorities such as the California Independent System Operator.

Fuel and Emissions

Originally designed to burn low-sulfur coal sourced from regional producers in the Wasatch Plateau and rail-delivered via freight carriers such as the Union Pacific Railroad, the plant’s fuel supply chain linked to coal-mining communities and companies like those engaged in the Powder River Basin export. Emissions profiles historically included sulfur dioxide, nitrogen oxides, particulate matter, mercury, and carbon dioxide relevant to Clean Air Act regulatory frameworks administered by the Environmental Protection Agency and state equivalents like the California Air Resources Board. Retrofit projects addressed controls including flue gas desulfurization (scrubbers), selective catalytic reduction systems developed by firms seen in projects for Duke Energy and Southern Company, and fabric filter baghouses analogous to installations in large utility units elsewhere.

Operations and Ownership

Owned by the Intermountain Power Agency, the facility’s power purchase agreements historically included long-term contracts with public agencies including the Los Angeles Department of Water and Power, the City of Riverside Public Utilities, and several municipal utilities across California. Day-to-day operations were contracted to utility operators experienced in large coal fleets; comparable operators include entities like NRG Energy and Calpine in other jurisdictions. Grid dispatch and scheduling interacted with regional markets managed by the California Independent System Operator and reliability coordination involving the North American Electric Reliability Corporation.

Environmental and Community Impact

Local communities in Millard County, Utah and advocacy organizations such as the Natural Resources Defense Council scrutinized impacts on air quality, water use, and land use patterns, echoed in public comment processes similar to proceedings before the Utah Division of Air Quality. Water withdrawals for cooling engaged water-rights institutions and river basin management discussions reminiscent of cases involving the Colorado River Compact stakeholders and western water law precedents like the doctrines adjudicated in state courts. Wildlife and habitat concerns involved species and agencies such as the U.S. Fish and Wildlife Service and were considered in environmental assessments akin to those under the National Environmental Policy Act.

Redevelopment and Future Plans

In response to California Global Warming Solutions Act of 2006 mandates, shifting fuel economics, and procurement changes by major purchasers such as the Los Angeles Department of Water and Power, plans were developed to convert the site from coal to natural gas and to add combined-cycle gas turbines with interconnection to projects in the California Independent System Operator footprint. Proposals have involved partnerships with infrastructure investors seen in transactions with companies like NextEra Energy and utilities engaging in repowering projects across the Western Interconnection. Redevelopment discussions also include potential roles for large-scale battery energy storage system deployments, hydrogen fuel blending pilots similar to pilot programs promoted by the U.S. Department of Energy and international demonstrations supported by agencies like the International Energy Agency.

Category:Coal-fired power stations in the United States Category:Energy infrastructure in Utah