Entergy Arkansas said it will close the state’s two largest coal-fired power plants, along with one gas-fired plant, by 2030 as part of a settlement with environmental groups that sued the utility in federal court for alleged violations of the Clean Air Act (CAA).

The Sierra Club and the Washington, D.C.-based National Parks Conservation Association filed the lawsuit in U.S. District Court for the Eastern District of Arkansas on November 16. The lawsuit said the utility violated the CAA in 2009, when it did work at the two plants without the proper permits. The environmental groups said the work caused emissions levels to increase at the plants.

Entergy Arkansas settled the suit later Friday, also agreeing to add renewable resources to its power generation portfolio. Arkansas Electric Cooperatives Corp. (AECC), which 35% of the electricity produced by the coal-fired plants, also supports the settlement, said Sandy Byrd, a spokesman for AECC. The cooperatives were not a party to the lawsuit because Entergy is majority owner and operator of the plants.

The coal-fired plants slated for closure are the 1,659-MW White Bluff Steam Electric Station in Redfield, Arkansas, and the 1,678-MW Independence Steam Electric Station near Newark, Arkansas. The utility also said it will close the 528-MW gas-fired Lake Catherine Power Plant in Malvern, Arkansas, by 2027.

The Sierra Club said the two coal-fired plants are the largest in the U.S. without modern scrubbing technology to reduce emissions. Entergy does have low-nitrogen oxide burners at the plants.

Kurt Castleberry, director of planning and marketing operations for Entergy Arkansas, told the Arkansas Democrat-Gazette that replacing the coal plants with renewable energy resources is more cost-effective than spending an estimated $2 billion to install advanced scrubbers at both plants.

“If you install the scrubber, you’re going to keep the plants running for a long, long time,” said Castleberry, who said each of the coal plants employs about 100 workers. The utility has wanted to keep the coal plants running and in recent years has argued in court and in regulatory proceedings that the plants were needed to ensure reliable power to the region. But Castleberry said lower costs for solar power and other renewables make replacing the lost generation with cleaner energy more prudent.

“It’s a very good economic deal for our customers,” Castleberry said.

Millions in Savings

Glen Hooks, executive director of the Sierra Club in Arkansas, in a conference call with media said closing the coal plants is “a matter, I think, of being realistic and responsible.” Entergy Arkansas in a statement said the settlement benefits its customers because it avoids millions in legal costs and also means the utility saves the “hundreds of millions of dollars” in costs to add more emissions controls to bring the plants in compliance with emissions rules.

Castleberry said the utility could find other uses for the coal and gas plant sites, including more gas-fired generation. He said a move toward renewable generation also includes utility-scale batteries.

Alison Melson, a spokesperson for Entergy Arkansas, said the utility will build new generation “wherever it makes the most economic sense for our customers.”

The environmental groups in their lawsuit said, “As a result of their coal combustion, both plants release into the atmosphere significant amounts of air pollution.” Entergy’s air pollutant report to the U.S. Environmental Protection Agency said White Bluff emitted 46.2 million pounds of sulfur dioxide (SO2), 22.8 million pounds of nitrogen oxides (NOx), and 18.3 billion pounds of carbon dioxide (CO2) in 2017. The report said the Independence plant emitted 39 million pounds of SO2, 17.3 million pounds of nitrogen oxide (NOx) and 16 billion pounds of COin 2017.

Upgrades Near El Dorado Plant

Most of Entergy’s power generation comes from a 1,988-MW gas-fired plant in El Dorado, Arkansas. The utility is in the midst of work in that area, including upgrades to almost three miles of 115kV transmission line, along with equipment in two substations.

Entergy also operates the 1,823-MW Nuclear One plant in Russellville, Arkansas. That plant earlier this year was cited for poor performance and other problems in the U.S. Nuclear Regulatory Commission’s annual assessment of the nation’s nuclear fleet. The Union of Concerned Scientists, a public policy group that focuses on environmental and energy issues, earlier this month put Nuclear One of a list of nearly 30 U.S. nuclear plants it considers at risk of closing over the next decade due to poor economics.

Entergy as part of Friday’s settlement must ask regulators for approval of 800 MW of renewable power generation, though 181 MW of that total already have been approved by the Arkansas Public Service Commission.

Darrell Proctor is a POWER associate editor (@DarrellProctor1, @POWER magazine).