The best wind resources in the U.S. are in the country's more sparsely populated center, but electricity demand is concentrated on the East and West Coasts.

That means that the continued growth of the U.S. wind market will require major new transmission lines — a big challenge, because such projects can take more than a decade to bring from concept to reality. The complex multi-party permitting process can see even well-designed projects derailed along the way. 

That’s why the wind industry is celebrating last week’s win of a key permit that helps pave the way for a $3 billion transmission project, aimed at bringing several gigawatts of new wind power from Wyoming to West Coast electricity markets. 

On Friday, the TransWest Express Transmission Project won unanimous approval from the Wyoming Industrial Siting Council, the last of the state and federal approvals needed to move forward with its 3-gigawatt plan. This could allow the project to begin construction as early as next year, and open for business as early as 2023, Kara Choquette, communications director for TransWest, said in a Monday interview.

First proposed in 2005, TransWest Express would stretch 730 miles from southwestern Wyoming through Colorado and Utah, to its connection to western grids at Nevada’s Hoover Dam. It will be a combination of high-voltage direct current and high-voltage alternating current systems, capable of carrying up to 3 gigawatts of power when it’s complete. 

TransWest is a subsidiary of the Anschutz Corp., the private holding company of oil billionaire Philip Anschutz, which bought the rights in 2008. Anschutz Corp. also owns the Power Company of Wyoming, a subsidiary that’s developing the 3-gigawatt Chokecherry and Sierra Madre Wind Energy Project in southwestern Wyoming, in a region that’s been identified as one of the best wind resources in the country, Choquette said. 

While the two companies are separate, their future prospects are closely intertwined, since the key market for that wind power will lie outside the state — primarily in California, which is hungry for clean energy to meet its statewide carbon-reduction ambitions.

Besides the TransWest and Chokecherry projects, there are at least two other transmission projects being worked on to carry power from Wyoming westward, including the Zephyr Power Transmission Project, which has been in the works since 2011, and the proposed Gateway West and Gateway South projects from utility Rocky Mountain Power.  

About two-thirds of the TransWest route lies on federal land, Choquette noted, and the process of obtaining the federal environmental analysis, rights-of-way, easements and licenses to build on that land stretched from 2008 to last year. Wyoming was the last state in its path to grant approval, and the project now has to secure approval from the counties in Utah and Nevada it will cross before it can be built, she said. 

“There’s still more to go — there always is,” she said. “But these are very big milestones in de-risking the project and demonstrating that we can get things done.” 

The slow progress of major transmission projects has long been a thorn in the side of the wind industry. While the country saw a significant build-out of infrastructure between 2009 and 2015 that helped ease congestion from wind-rich regions to load centers, the next phase of planned expansions has been dogged by delays and roadblocks, according to Rob Gramlich, founder and president at Grid Strategies LLC. 

In recent years, the U.S. has built some small reliability-related lines, but large transmission projects to deliver clean energy have seen a string of setbacks and delays, noted Wade Schauer, Americas research director at Wood Mackenzie Power & Renewables.

This has been driving renewables developers themselves to invest in key transmission projects.

Last month, Siemens and Danish renewables investment fund Copenhagen Infrastructure Partners acquired the 2,100-megawatt SSO Green Renewable Rail transmission project from its developer to bolster its ambitious plan to use underground high-voltage direct current cables to streamline permitting and minimize landowner opposition. 

And last year, renewable developer Invenergy bought the Grain Belt Express project, meant to bring about 4 gigawatts of power from western Kansas to Indiana. That project has seen significant ups and downs in its permitting struggle, with the state of Missouri proving to be the key roadblock.

While Missouri's initial denial of the project was reversed by a legal ruling last month, the state’s legislature is on the verge of passing a law that would block the project’s use of eminent domain, putting its future in question.