The US Environmental Protection Agency on Monday approved a plan that calls for retiring a 750-MW coal-fired unit at the Navajo Generating Station in northeastern Arizona in 2019.
The EPA's action brings the planned coal-fired retirements in the Southwest by the end of the decade to about 2,760 MW, mainly through the Clean Air Act's regional haze requirements.
The plan to retire a unit at the 2,250-MW coal-fired power plant near Page, Arizona, is similar to a proposal for the 1,800-MW San Juan coal-fired power plant and the 1,480-MW Four Corners plant, which had three units totaling 560 MW retired at the end of last year. Both plants are in northwestern New Mexico.
In January 2013, the EPA set emissions limits for the Navajo plant that would require selective catalytic reduction technology, which Salt River Project, the plant's operator, estimated would cost about $1.1 billion, including new baghouses. At the time, the EPA said it would be willing to consider alternate proposals.
In response, a stakeholder group that included the Central Arizona Water Conservation District, the Environmental Defense Fund, the Gila River Indian Community, the Navajo Nation, SRP, the Department of the Interior and Western Resource Advocates developed a new plan for the plant.
The EPA said the plan, released a year ago, will cut nitrogen oxide emissions, a key contributor to regional haze, more than the agency's original plan. The plan calls for retiring the Navajo plant in 2044.
The stakeholders are "essentially pleased" with the EPA's final rule but will study it to make sure it does not contain any unexpected surprises, said David Modeer, general manager for the Central Arizona Project, which takes power from the Navajo plant.
The decision to retire one of the units early matches up with the needs of two utilities -- Los Angeles Department of Water and Power and NV Energy -- that intend to end their ownership in the plant as part of plans to shed their coal-fired generation. LADWP owns 477 MW and NV Energy owns 254 MW, totaling 731 MW, or slightly less than a single unit.
The Navajo plant's other owners include the Bureau of Reclamation (547 MW), SRP (488 MW), Arizona Public Service (315 MW) and Tucson Electric Power (169 MW). The Bureau of Reclamation's share of the plant is used to pump water along the Central Arizona Project from the Colorado River to central and southern Arizona.
