Colorado’s wind-power market and industry are posting strong performances in 2013, according to executives.

There are plans for more than 600 megawatts of new wind farms by four Colorado utilities — a 26 percent increase in generation.

“That is probably $1 billion in investment,” Sarah Cottrell Propst, executive director of the trade group Interwest Energy Alliance, said at the Colorado Energy Forum on Tuesday at the University of Denver.

The state already has 2,300 megawatts of wind generation, and utilities are looking to add to that number.

• Xcel Energy, the state’s largest electricity provider, has gained approval from state utility regulators to add 450 megawatts.

• The Platte River Power Authority has signed a deal for a 33-megawatts wind farm.

• Tri-State Generation and Transmission Association, the state’s second-largest electric utility, is reviewing bids for 100 megawatts of wind generation.

• Black Hill Energy has a request out for companies to provide 30 megawatts.

Colorado is projected to be among the top five states for wind installations, according to Tom Darin, an official with the American Wind Energy Association, a trade group.

A key element in wind power’s resurgence was the one-year restoration of the federal Production Tax Credit, said Anna Giovinetto, a vice president with Denver-based wind developer RES America.

The tax credit expired at the end of 2012, leading to a rush on projects before it lapsed.

Congress in January renewed the credit — equal to $22 for every megawatt-hour that a new wind farm produces — for one year.

“The volatility of the credit is a problem,” Giovinetto said. “It is difficult to make business decisions on a one-year timeline.”

The production tax credit, however, makes wind power highly competitive, Darin said, with prices equal to the cheapest new power — natural gas turbines.

Under the tax-credit extension, projects must begin before the end of 2013, but much of the activity will take place in 2014, Giovinetto said.

That is also good news for the wind-turbine manufacturing industry, said Susan Innis, a spokeswoman for Vestas Wind Energy Systems.

The Aarhus, Denmark-based company, which has four factories in Colorado, in 2012 trimmed its workforce by 40 percent, to 1,000.

Since January, Vestas has hired 200 people and is continuing to add workers as needed, Innis said.

Mark Jaffe: 303-954-1912, mjaffe@denverpost.com or twitter.com/bymarkjaffe