DES MOINES — MidAmerican Energy plans to add 1,000 wind turbines in Iowa, a project that the company says will cost $3.6 billion and move it closer to providing 100 percent renewable energy to its customers.

MidAmerican CEO Bill Fehrman, joined by Iowa Gov. Terry Branstad and state economic development director Debi Durham, announced the proposed project Thursday at a news conference in a building at the base of a wind turbine at the Iowa State Fairgrounds.

The project, which Branstad said would be the largest economic development project in Iowa’s history, must be approved by the state utilities board.

“Our company has a very bold dream to some day deliver 100 percent renewable energy to our customers,” Fehrman said. “We know it’s the right thing to do, and we know it’s critical to take this giant step forward.”

Fehrman said the project would add 2,000 megawatts of wind energy in Iowa and will move the company to producing wind energy equal to 85 percent of annual customer sales.

The project can be completed without additional cost to customers, as the entire $3.6 billion will be recouped through federal tax incentives over 10 years, Fehrman said.

Ferhman declined to say where in Iowa the new wind turbines will be added, saying the company is in negotiations with landowners and other parties. He said that if the state utilities board approves the project by this fall, construction will begin next year and the vast majority of the project will be completed in 2017 and 2018.

Durham praised the proposal as “audacious.”

“This announcement solidifies Iowa’s role in leading the nation in clean energy,” Durham said.

More than 30 percent of Iowa’s electricity is generated by wind energy, the highest rate in the nation.

“In Iowa we don’t just dream, we make things happen,” Branstad said. “We make history. Today’s a great day for Iowa.”

Praise for the proposed project also poured in from other organizations and elected officials, including the state’s senior U.S. senator, who authored the federal tax incentive for wind energy projects.

“The potential for wind energy in Iowa and the nation looks endless,” U.S. Sen. Chuck Grassley said in a statement. “I’m grateful for the latest investment in the people of Iowa.”

Added U.S. Rep. Dave Loebsack in his own statement, “I am pleased this investment will bring more jobs for our highly skilled workforce, as well as create additional homegrown and affordable energy sources.”

The Sierra Club, which advocates for natural resources and the environment, also praised MidAmerican for its investment in renewable energy.

“MidAmerican made clean energy history today,” Bruce Nilles, senior director for Sierra Club’s “Beyond Coal” campaign, said in a statement. “Iowa and MidAmerican’s rapid transition from dirty coal to affordable wind offers a game-changing new model for how utilities will reach 100 percent renewable energy more quickly than anyone would have predicted.”