Colorado is one of 11 states that generated at least 10 percent of its total electricity from wind last year, according to an analysis by the Energy Information Administration.

Colorado is one of 11 states that generated at least 10 percent of its total electricity from wind last year, according to an analysis by the Energy Information Administration.

Wind produced 14 percent of Colorado’s electricity in 2015, according to the EIA report released last week, putting it No. 9 among the group of states. Spurred by renewable-energy goals, Colorado’s electric generation is moving more quickly toward wind than other states, particularly in the mountain West, where natural gas is filling in the coal gap.

But while wind generation seems like it’s on a path of exponential growth, experts say a lack of accessible transmission lines could be the one factor to stymie that expansion in Colorado, even as the cost effectiveness and ease of implementation of the renewable resource improves.

Wind-produced electricity accounted for about 6 million megawatt-hours of Colorado’s total 52.6 million megawatt-hours generated in 2012, the EIA reported. In 2015, that number jumped to 7.5 million megawatt-hours. And plans are in the works to build more turbines on the Eastern Plains, which will dramatically increase production.

“I think that we can expect to see further expansion of wind energy resources in the West and in Colorado,” said Gwen Farnsworth, senior energy policy adviser for Boulder-based Western Resource Advocates. “The reason that we’ve seen a rapid growth of wind generation in Colorado in particular is it has recently been extremely cheap and cross-competitive against other types of wind generation.”

Wind-energy generation systems — as opposed to solar — are almost exclusively built on a large scale, leading to prices that can compete with fossil fuels, experts say. That has led to big increases in Colorado and across the country, relative to solar, which has been slow to proliferate even though it is becoming more affordable.

Farnsworth said there really isn’t a ceiling on how much wind energy and other renewable sources can be used to power Colorado’s grid. There have been questions about infrastructure with wind, however, because of a dearth of ways to actually move electricity produced on the wind-swept prairie to the high-demand Front Range.

“One of the big problems throughout the area is that places that have high wind energy are not necessarily close to those high transmission lines,” said Mark Smith, a professor of environmental and resources economics at Colorado College.

Smith says it can be expensive to buy up right-of-way on private land to move power to the “doughnut” of power lines that runs along the Front Range southwest to Los Angeles and back. But that hasn’t seemed to slow down the use of wind generation in the West.

The EIA reports that nationally, wind’s part in energy production has risen every year since 2001, pumping out 190,927 gigawatt-hours in 2015 and accounting for 4.7 percent of net U.S. electric power generation.

“This level represents a doubling of wind’s generation share since 2010, when the share was 2.3 percent,” the EIA says. “Based on monthly data through July, wind has provided 5.6 percent of U.S. generation in 2016.”

Wind sources added 6.7 billion kilowatt-hours to the generation mix in Colorado during the past decade — more than what wind added in Arizona, Idaho, New Mexico, Nevada, Montana and Utah combined.

Iowa had the largest wind generation share last year, at 31.3 percent, ahead of South Dakota, with a 25.5 percent share of its electricity generated by wind, and Kansas, which was at 23.9 percent.

Texas and New Mexico are set to exceed 10 percent wind generation share this year, the EIA says. Wind generation in Texas, the highest wind electricity-producing state, made up 24 percent of the national total wind generation, but just 9.9 percent the electricity generated within its borders in 2015.

“Wind is a big deal because fossil fuel prices are so volatile,” said Frank Swain, energy advocate for Conservation Colorado. “Wind has an edge against that.”

Utilities can also get tax breaks for using wind generation, Swain said, which don’t seem to be going away any time soon.

In Colorado, renewable energy sources have been increasingly used as the state works to meet its own goals and prepare for the implementation of the Environmental Protection Agency’s embattled Clean Power Plan. The legislature has mandated that 30 percent of the state’s electricity from investor-owned utilities must come from renewable sources, and 20 percent for other utilities, by 2020.

Xcel Energy, the state’s largest utility, says it expects to exceed those goals and that by 2020 wind will represent 28 percent of its electricity production; solar will account for another 7 percent. The utility’s wind generation capacity has shot up to 2,566 megawatts of capacity this year from 1,265 megawatts in 2010.

One megawatt of generation generally serves about 750 residential customers.

Jack Ihle, director of environmental policy for Xcel, said wind has been a highly attractive option in Colorado both because of the state’s weather and availability of land available for turbines relatively close to the metro area.

Take, for example, Xcel’s 600 megawatt Rush Creek Wind Project, spanning Cheyenne, Elbert, Kit Carson, and Lincoln counties. A 90-mile transmission line will connect the network of wind turbines to a substation near Deer Trail in Arapahoe County that will bring the power to Front Range communities.

While it might seem like Xcel is focusing more on wind more than solar in Colorado, Ihle said that doesn’t take into account the full picture.

“I don’t know if we would necessarily say it’s more attractive at this point,” he explained. “The wind and solar we have on our system is a function of economics, and it’s also a function of history. It’s not really a question of one being easier than the other. Both fit into our context for resource planning.”

Ihle said wind has been a rising technology over the past 20 years while utility-scale solar is relatively new.

According to the federal report, few other renewable fuels make up 10 percent or more of states’ electricity generation; hydropower is the exception. Solar-powered electricity generation accounted for 10 percent of California’s electricity generation in 2015, the EIA says.

“I think we can anticipate seeing additional solar resources in Colorado in the future,” Farnsworth said.