MidAmerican Energy is investing $12 billion in wind-energy generation, but environmental groups question the utility's 100-percent renewable energy plan, given its large, continued reliance on coal plants for power.
The Iowa Environmental Council and Environmental Law & Policy Center say the Iowa Utilities Board should require MidAmerican to begin phasing out its fleet of coal-powered plants, replacing fossil fuel generation with new wind power, solar energy and utility-scale renewable energy storage.
MidAmerican announced in May it would invest $922 million more in wind energy, the last phase in its vision "to generate renewable energy equal to 100 percent of its customers’ usage on an annual basis."
It would be the first U.S. investor-owned electric utility to meet the goal.
With the investment, MidAmerican said it will have pumped $12.3 billion in wind energy since 2004 and "own the most wind-generation capacity of any U.S. regulated utility."
But MidAmerican still gets 30 percent of its electricity from coal, the environmental groups say. About half MidAmerican's power comes from wind generation.
"The 100 percent renewable energy vision is a bit of a gimmick," said Josh Mandelbaum, an Environmental Law & Policy Center senior attorney, "It's pretty misleading if MidAmerican is giving customers the impression that's all they have to do."
MidAmerican hasn't retired any coal plants since 2016, when it announced its goal, the group said. The Des Moines-based utility anticipates reaching the goal by 2020.
MidAmerican said the utility has cut its "carbon intensity in half."
"That will only increase as we continue to add to our wind fleet," MidAmerican said in a statement, adding that it has retired two coal units each at Walter Scott Jr. and Neal Energy Center "in the last several years."
The utility said it needs a "diverse generation portfolio that utilizes wind, natural gas, nuclear and coal-fueled plants" to provide reliable service in times of "low wind."
The environmental groups said MidAmerican, owned by Berkshire Hathaway, ranks among the top 20 utilities nationally for the size of its coal plant fleet, owning all or part of five coal-powered plants, with 4,465 megawatts of power generation capacity.
"Utilities around the U.S. are announcing coal retirements on an almost daily basis. By betting on coal, MidAmerican will only climb in this undesirable ranking," the groups said in a statement.
MidAmerican points to its wind investment for helping to hold down customers' rates.
But MidAmerican won't see the benefits without continuing to diversify its energy lineup with renewable energy, said Kerri Johannsen, the Iowa Environmental Council energy program director.
"Many of the benefits MidAmerican claims ... are unlikely to occur unless coupled with retirement of coal capacity," Johannsen said in a filing with the Iowa Utilities Board.
The board must consider whether to approve MidAmerican's wind investment.
MidAmerican has helped Iowa lead the nation in wind generation.
Wind provided 37 percent of Iowa’s total electric generation in 2017, a larger share than in any other state, according to the Energy Information Administration, a federal agency.
And Iowa's coal use declined to 45 percent last year from 76 percent in 2008. It's still the state's largest source of energy, followed by wind, the agency says.
Other utilities are retiring coal plants, including Consumers Energy in Michigan, and MidAmerican’s sister Berkshire Hathaway subsidiaries, NV Energy and Pacificorp, the groups say.
"Clearly, this approach is possible as other large utilities — including other Berkshire-owned utilities — are moving in this direction," the groups said in their filing.
Their continued investment in renewable energy, along with coal plant retirements, will make them more attractive to companies looking for clean energy sources, the Iowa Environmental Council and Environmental Law & Policy Center said.
Google, Microsoft and Facebook, all large energy users, have said Iowa's low-cost clean energy was among their reasons for building data centers in the state.
Iowa utilities "must continue to show leadership in clean energy innovation or the state will fall behind other emerging leaders,” Johannsen said.