What is actually being built

You pay a Rocky Mountain Power bill, and most of the electricity behind it still comes from coal and gas burned fairly close to home. So it is fair to ask what a roughly 732-mile transmission line being built across southern Wyoming does for you. The honest answer is that it was designed mostly to send power the other way, out of the state and toward the Southwest.

The line is the TransWest Express project, a high voltage direct current link (direct current, meaning the power flows one steady direction rather than reversing many times a second the way ordinary household current does). It runs from near Sinclair, in Carbon County, toward the Eldorado Valley south of Las Vegas, crossing Wyoming, Colorado, Utah, and Nevada. The developer says it is sized to carry on the order of 3,000 megawatts, enough in round numbers for a few million homes, and construction began in 2023 with a target in the neighborhood of 2027 at last public word.

How a direct current line gets built

Building across four states is not one job but many. Crews work the route in segments, stringing conductor between towers where the ground, the weather, and the permits all line up, which on the high plains means fighting wind and short seasons more than anything else. Because the heart of the line is direct current, it cannot simply plug into the alternating current grid at either end.

That is the job of the converter stations, large fenced yards of equipment that turn alternating current into direct current for the long haul and back again at the far end. There is one planned near the Wyoming terminal and one near the Nevada terminal, and they are among the slower, more specialized pieces of the whole project. Watching their progress is a better gauge of the real timeline than counting towers, because a line with no converters energizes nothing.

The wind that waits behind it

A line this big is only worth building if something is waiting to fill it. In this case that something is the Chokecherry and Sierra Madre wind project south of Rawlins, a very large build-out that its owner, Power Company of Wyoming, has described in phases totaling up to roughly 3,000 megawatts across hundreds of turbines. The wind farm and the line are separate companies under related ownership, built so the wind has somewhere to go.

For a Wyoming reader, the practical shape of this is clear. The turbines rise on ranch land in Carbon County, the power leaves the state on the line, and what stays behind is construction work, property and sales tax, and Wyoming's wind electricity generation tax, about one dollar per megawatt hour and the only tax of its kind in the country. Your roof and your meter are mostly spectators here, which is not a complaint, just the truth of an export project.

Worth watching this month

1. Watch the TransWest Express project updates page for word on converter station progress at the Wyoming and Nevada ends, which the developer posts irregularly rather than on a fixed calendar.

2. Watch Power Company of Wyoming's Chokecherry and Sierra Madre updates for turbine counts in the next phase, figures that have been revised before and could move again.

3. Watch the Bureau of Land Management's Wyoming office for any right-of-way or route amendment notices, usually routine paperwork but occasionally the first sign of a real change.

4. Watch Rocky Mountain Power's resource planning filings at the Wyoming Public Service Commission, which say more about your actual bill than this export line ever will.

5. Watch for the first energization or commissioning milestone, still likely a year or more out at last public word and the single date that actually matters.

Questions readers ask

Will this line lower my electric bill?

Probably not directly. It was built mainly to carry Wyoming wind to markets in the Southwest, so most of what stays in-state shows up as tax revenue and construction jobs rather than a smaller Rocky Mountain Power bill.

Why direct current instead of a normal line?

Over very long distances, high voltage direct current loses less energy than ordinary alternating current. That makes it attractive for a haul of several hundred miles, at the cost of building converter stations at each end.

Is the wind farm the same thing as the line?

No, but they are linked. The Chokecherry and Sierra Madre wind project near Rawlins and the TransWest line are separate companies under related ownership, built so the wind power has a path to customers.

When will it be finished?

At last public word the developer pointed to roughly 2027. Large transmission schedules slip often, so treat any single year as a target rather than a promise.

Does Wyoming get anything from power that leaves the state?

Yes. Wyoming levies a wind electricity generation tax of about one dollar per megawatt hour, the only state with one, and it generally applies after a turbine has been running for a few years.

Sources of record

  • Bureau of Land Management, TransWest Express project (federal)

    The federal agency that reviewed the route and granted rights-of-way across public land; look here for environmental records and any route changes. www.blm.gov/programs/energy/renewable-energy/transmission-projects

  • TransWest Express LLC, project website (developer)

    The developer's own maps, segment descriptions, and periodic construction updates, including the converter stations. www.transwestexpress.net

  • Power Company of Wyoming, Chokecherry and Sierra Madre (developer)

    The wind project that the line is meant to carry; check here for phase and turbine-count updates. www.powercompanyofwyoming.com

  • Western Area Power Administration (federal)

    The federal power marketer involved in moving power across the West; useful for how the line fits the regional grid. www.wapa.gov

  • Wyoming Public Service Commission (state agency)

    Where Rocky Mountain Power files its resource and rate plans, which bear far more directly on your bill than this export line. psc.wyo.gov

  • Western Electricity Coordinating Council (grid reliability)

    The reliability coordinator for the Western grid that Wyoming sits in; context for how new lines are studied and planned. www.wecc.org