PacifiCorp's Seven Mile Hill wind farm in Carbon County generates 111 megawatts of electrical power. (Dustin Bleizeffer/WyoFile)

Having recently cleared key legal and permitting hurdles, developers are slated to begin construction of two major high-voltage transmission lines connecting Wyoming to several states in the West. When completed, the Gateway South and TransWest Express transmission lines will open the door to a major expansion of wind energy development in the Cowboy State, industry officials say.

“The TransWest Express project opens the ability for Wyoming wholesale electricity supplies to reach new markets, like southern California, Arizona and Nevada, that the state is not directly serving today,” Power Company of Wyoming Communications Director Kara Choquette said.

The $3 billion, 732-mile long TransWest Express transmission line will transport electricity from Power Company of Wyoming’s Chokecherry and Sierra Madre Wind Energy Project in south-central Wyoming, as well as other potential new wind energy facilities. Situated in Carbon County, the project’s 900 wind turbines with a total capacity of 3,000 megawatts will be the largest onshore wind energy facility in the United States.

The TransWest Express transmission line will connect wind energy from south-central Wyoming to southwestern states. (TransWest Express LLC)

After years of negotiations, TransWest Express LLC recently secured a right-of-way agreement with a large private landowner in western Colorado. Construction of the TransWest Express transmission line could begin as early as 2023, according to company officials. TransWest Express LLC and Power Company of Wyoming are both subsidiaries of Anschutz Corp. 

Meantime, Berkshire Hathaway-owned PacifiCorp received “certificates of public convenience and necessity” from the Wyoming Public Service Commission May 10 for its Gateway South and a segment of its Gateway West lines. Both are part of PacifiCorp’s larger Energy Gateway transmission expansion project to add more than 2,000 miles of high-voltage power lines connecting Wyoming wind energy to five other western states in PacifiCorp’s service territory.

Construction will begin this summer, according to PacifiCorp. Both Gateway South and Gateway West “Segment D.1” are slated to be operational in late 2024. 

Shift from coal to wind

The added transmission capacity and increased number of “on-ramps” and “off-ramps” that the transmission lines would provide to Wyoming and the western grid set the stage for a major buildout of wind turbines in the state. When completed, that extra capacity and interconnectivity would also provide PacifiCorp — and possibly others — the ability to retire coal-fired power units in the state by meeting several new state-level power delivery and reliability requirements, according to University of Wyoming energy economist Rob Godby.

PacifiCorp’s Gateway South transmission line is part of the utility’s larger Energy Gateway Transmission project. (PacifiCorp)

“When you have a more flexible system, it’s just less likely that you need coal,” Godby said. “You can rely on a more flexible set of generation alternatives, and that old fossil fuel backbone [coal-fired power] is less relevant.”

Adding interstate transmission capacity — and therefore boosting the ability to move power in and out of Wyoming as needed — is integral to PacifiCorp’s plans to meet the state’s reliability standards, according to PacifiCorp spokesperson David Eskelsen.

“The Gateway South and Segment D.1 transmission projects were modeled in the 2021 [integrated resource plan] as key to system reliability as the energy transition is expected to continue,” Eskelsen told WyoFile.

PacifiCorp says it will retire 14 of its coal-fired power units across several states, including several in Wyoming by 2030, and a total of 19 by 2040. The regulated utility plans to add more than 3,700 megawatts of new wind power by 2040 throughout its six-state region, including in Wyoming.

Wyoming wind

Wyoming has some of the best wind resources in the Continental U.S., according to Jonathan Naughton, professor of mechanical engineering and director of the Wind Energy Research Center at the University of Wyoming. Several regions of the state — mostly in the southeast — have “wind capacity factors” of more than 50% compared to 35% in other interior states.

Wind bends a flagpole at the historic Virginian Hotel in Medicine Bow in December 2021. (Dustin Bleizeffer/WyoFile)

“It means that the turbines that they put up are running at full capacity more often,” Naughton said.

Wyoming wind also tends to be more consistent during winter months and during evening hours throughout the year, providing a balance to power demands in other western states. When solar power generation drops off in the evenings in California, for example, Wyoming wind can backfill the power supply. The same dynamic applies between eastern Wyoming and the Colorado Front Range.

“There’s some attractive things about combining solar and wind from Wyoming,” Naughton said.  “And if you build out a really robust transmission system, it’s easy to move power around, and it solves a lot of these issues with variability.”

Wyoming’s electrical export

Wyoming exports about three-fifths of the electricity generated in the state, according to the U.S. Energy Information Administration. A supermajority of Wyoming’s total power generation comes from coal-fired power plants.

A truck hauls a wind turbine blade through Medicine Bow in July 2020. (Dustin Bleizeffer/WyoFile)

But the state’s electrical generation profile is rapidly changing.

Coal accounted for 97% of the state’s power generation in 2003, according to EIA. There was a lull in wind energy development in the 2010s, but since 2019 the state has more than doubled its wind energy generation capacity.  Now at more than 3,000 megawatts, wind accounts for nearly a third of the state’s total electrical generation capacity.

Much more wind power is on the way. Wyoming could see an additional 6,000 megawatts of new wind power capacity by 2030, according to those close to the industry. Although not every wind power proposal will come to fruition, the inevitability of major interstate transmission projects connecting Wyoming wind resources to western states will help shift the state from a majority coal power exporter to a majority wind power exporter, UW’s Godby said.

“The reality is that [more electrical transmission] creates both the capacity to develop more renewable energy, and in different places,” Godby said.
Meantime, PacifiCorp has dialed back electrical generation output from some coal-burning units, including at Jim Bridger, making more room for Wyoming-originating wind energy on existing interstate electrical transmission lines.

Dustin Bleizeffer

Dustin Bleizeffer is a Report for America Corps member covering energy and climate at WyoFile. He has worked as a coal miner, an oilfield mechanic, and for 22 years as a statewide reporter and editor primarily...

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  1. Great rebuttal to all those who doubted Loyd Drain and the Wyoming Infrastructure Authority. Good work old friend!

  2. How will the tax proceeds and jobs from the wind turbines compare to the lost taxes and jobs resulting from displaced coal production? In other words, why is this good for Wyoming?

  3. Also wind generating manufactors are idling or closing plants due to no demand. Plus supply chain issues on materials. Solar panels are delayed on Tariff issues. So all this is screwed up on planning. But Biden’s admin is that way. Look at damages they caused down in New Mexico with “controlled burn”. What a mess.

  4. The wildlife impacts of wind farms are largely ignored because of the warm fuzzy “green energy” stamp given by the media. Look at the footprint of the average windfarm. It’s a massive amount of land, now void of deer, antelope and sage grouse. And yet we consider this progress? Why isn’t nuclear power a better answer? Amazingly small footprint for an immense amount of power production. In fact, one nuclear power plant in Arizona produces more power than all the 900 Carbon County wind turbines talked about in this article. While wind energy may sound green to humans, it’s certain death to Wyoming’s high desert wildlife.

  5. Personally, I am a strong alternative energy advocate. Nevertheless, this new Wyoming energy boom will impose even greater impacts on many important wildlife resources than other forms of energy extraction in Wyoming — especially golden eagles and other winged wildlife. Wind farms in Wyoming are currently being sited on some of the most vital golden eagle breeding, migration and wintering habitats found anywhere in North America. Eagles are already being killed by Wyoming wind farms and there is little transparency on actual mortality numbers as it is, but the levels of turbine-killed eagles are undoubtedly higher, perhaps much higher, than either reported or predicted. The proposed massive expansion of new wind farms will have cumulative, profound long term impacts on both resident Wyoming golden eagle populations as well as those eagles that migrate through and overwinter in our state. Proposed new projects will further fill-in undeveloped gaps in crucial eagle habitat; and, in parts of Wyoming, will result in a largely contiguous turbine foot print that will exponentially elevate risks for eagles and other flying species that use or pass through those habitats.

    The U.S. Fish and Wildlife Service, the principal agency charged with the conservation and protection of golden eagles has largely abdicated it’s legal responsibilities in this matter. The Service is facilitating a new, additive, and excessive source of mortality by authorizing wind farms to kill an annual number of eagles per project based on “modeled” population impact assessments. Yet, that modeling likely seriously misrepresents real world consequences, especially for eagles that actually nest close to wind farms. And, if the numbers of eagles killed by wind farms actually meet the level of annual “take” permitted by the Service, thousands of eagles will be killed over the decades of project life for existing and proposed Wyoming wind projects .

    Wyoming is blessed with golden eagle populations and key habitats that are essential for the long range well-being of eagles and a host of other wildlife species. It makes no sense to overlay such sensitive, highly important wildlife habitats with wind farms when there are so many alternative wind sites, both inside Wyoming (eastern cultivated lands), and elsewhere throughout the U.S. that pose far less potential harm to eagles and other wildlife!

    1. Mike Lockhart and I have been acquainted for years and I know him to be a top-notch wildlife biologist. I have no reason at all to doubt what he says. It saddens me a great deal. I wish that there was a comprehensive planning framework that would cause windfarms to be located where they would do the least harm to wildlife, but unfortunately there seems to not be. Perhaps more rigor by the Fish & Wildlife
      Service would help. How can we push for that? So would national and state policies that encourage energy conservation and growth of residential solar energy capacity instead of industrial windfarms.
      Here’s a scenario that makes me want to retire coal plants as fast as possible, even at some cost in raptor deaths. Warmer temperatures (already here, and certain to increase) will mean more and larger wildfires. Forest fires grab our attention, but large range fires have also been burning in the Great Basin and Intermountain, and they’re inevitable in Wyo too. They’ll kill sagebrush and weaken native grasses and forbs over large areas, and cheatgrass (already widespread and increasing in the state) will thrive. The cool, moist springs in which sagebrush seedlings become established will become rarer, and large areas will recover to sagebrush only slowly, if at all. Plus, cheatgrass is extremely flammable and increases fire frequency, so native plants will continue to decline. This downward spiral is exactly what has happened over much of the former sagebrush country of the Great Basin and Intermountain in the past century, even without elevated temperatures. Cheatgrass-dominated grasslands have less prey for raptors, and are nearly worthless for most songbirds. And livestock carrying capacity is low. I certainly don’t know to what degree this will happen, but I have no doubt that this is the future to some degree. The trade-offs we face are truly distressing.

  6. End of cheap electricity is here. Get ready for $500 monthly electric bills/rolling blackouts or brown outs that destroy applaiances an Gas heating bills in $600-$700 month in winter time. Thank Joe for it.

    1. @ Larry Skow:
      Yeah, it’s all Joe’s fault
      Just like the price of gasoline and diesel – it’s all Joe’s fault. It certainly couldn’t be price gouging by the energy companies.
      And who cares if burning coal is a primary factor in elevated CO2 levels in the atmosphere and the mercury is elevated in all the water on earth? If we can just have “cheap” power, everything’s okay.
      Why don’t we look at using some of that power in Wyoming, instead of sending it elsewhere? Dang! Not much of a population and virtually no manufacturing.

    2. Biden has nothing to do with it. This transition has been coming for decades.

      The Sierra Madre/Chokecherry and Transwest/Gateway project were proposed during the Bush administration.

      Since 1976, the US has invested $236.7 billion in coal energy research: https://www.ej-energy.org/index.php/ejenergy/article/view/12

      The US has invested $3 billion to wind energy research in the same time period: https://www.sciencedirect.com/science/article/pii/S0306261919321373

      Wind is 3x cheaper with subsidies (for coal AND wind) stripped out of the equation: https://www.lazard.com/perspective/levelized-cost-of-energy-levelized-cost-of-storage-and-levelized-cost-of-hydrogen/