CASPER — Wind farms have been popping up all over Wyoming. Solar arrays, for the most part, haven’t. 

The state’s wind turbines supply thousands of megawatts of power to the electric grid. But the 97.9-megawatt Sweetwater Solar project, which became Wyoming’s first utility-scale solar farm when it was completed in 2018, still makes up most of the grid-connected solar supply. 

There are a number of reasons why wind is, by far, the dominant source of clean energy in Wyoming. The main reason is simple: Wyoming is just really, really windy. 

“Wind is our most outstanding renewable resource in this state,” said Connie Wilbert, director of the Wyoming chapter of the Sierra Club. “Solar is good here. But it’s affected by latitude, simple as that. We’re a northern state. And the farther north you go, the more seasonal difference you see.” 

Despite its latitudinal disadvantage, Wyoming’s clear skies and high elevation make it one of the better states for solar power generation. But its contentious energy politics and limited transmission infrastructure have likely caused potential solar developers to turn instead to friendlier, sunnier states farther south. 

The state’s mixed messaging around renewables has been one worry for the solar industry. State Sens. Larry Hicks and Ogden Driskill and seven state representatives seeking to preserve the coal economy introduced a bill in 2017 that proposed banning large wind and solar projects in the state by 2019. Though the bill soon died in committee, it and other, less extreme proposals have left developers uncertain about the political feasibility of utility-scale solar in Wyoming.

Amid repeated attempts by state policymakers to boost state revenue by raising the tax imposed on wind power generation, solar developers are also concerned about efforts to institute a similar tax on their projects — especially as the share of the state budget contributed by natural resource revenue continues to decline, forcing legislators to search for alternative funding sources. Transmission is another hurdle for solar projects, though the infrastructure has become more abundant in Wyoming in recent years, due in part to new wind development. Before constructing new transmission, companies are often required to obtain siting approval from private landowners along with numerous permits at the state and federal levels — a lengthy and expensive process. 

To connect to existing transmission infrastructure, projects must be sited near transmission lines that can handle the additional electricity supply. 

“The nice thing is, the wind and solar are a bit complementary in terms of when they’re producing power,” said Bruce Parkinson, a professor of chemistry and energy resources at the University of Wyoming. “Wind in Wyoming is pretty much late evening, early night — and solar, of course, is only during the day. And so any extra transmission capacity can be pretty optimally used if you have both wind and solar connected to it.” 

Wind power achieved commercial viability earlier than solar did, but with the costs of both electricity sources continuing to fall, they’ve become competitive with natural gas and, in many places, cheaper than coal and nuclear. But price isn’t the only obstacle. The variability of wind and solar continues to be a major challenge for utilities. 

Rapid advancements in utility-scale battery storage, which enables electricity suppliers to save energy when supply exceeds demand and release it onto the grid when demand surpasses supply, have helped to neutralize the volatility of renewables. 

And green hydrogen production, a different type of energy storage that uses excess renewable power to generate combustible hydrogen, is also gaining traction among electricity providers. 

In July, the Wyoming Energy Authority awarded $1.5 million in grants to three companies for feasibility studies on blue and green hydrogen development in the state. And Rocky Mountain Power, Wyoming’s main electric utility, will include hydrogen in the biennial Integrated Resource Plan it plans to release in September. 

Despite the current storage constraints, utilities and private developers are continuing to expand their solar footprints in sun-baked states like California, Arizona and New Mexico. 

The disparity between wind and solar in Wyoming persists in part because the generation capacity operated by PacifiCorp, parent company to Rocky Mountain Power, spans six Western states — enabling it to harness renewables wherever the resources are strongest. 

“There are some sites in Wyoming that are potential good sites for solar but, quite frankly, most of the renewable resources that have scored well in Wyoming have been wind sites,” said Dave Eskelsen, a spokesman for Rocky Mountain Power. 

Much of PacifiCorp’s solar development is concentrated in Utah, which gets some of the best sun in the country. In Wyoming, meanwhile, wind power remains PacifiCorp’s priority. Solar is relegated primarily to rooftops and other similarly small-scale applications, like pumping water for cattle on ranches. 

James L. Reitsma, president of the recently founded Legacy Group, doesn’t want to wait for someone else to build those solar farms. The Laramie resident, who says he has lived in the state since 1971, is proposing a 250-megawatt solar farm near Riverton, on one square mile of land that is privately owned by his company. 

Concerned about climate change and his grandchildren’s futures, Reitsma views solar as a safe source of clean energy for the state. 

“If you lived here at least for as long as I have, you love the state, you love the outdoors, you love the clean air — or you would love to keep it that way. And I think we’ve all got to do all we can do to keep it there,” he said. 

The project faces a lengthy permitting process, but if approved, the 30,000-panel array would become the biggest solar farm in Wyoming and one of the largest in the country.