Wind farm sprouts on Rattlesnake Flat

ADAMS COUNTY — The name Rattlesnake Flat evokes bleak and remote desolation — lonely cacti dotting a dusty landscape, the occasional tumbleweed rolling past a cattle skull slowly bleaching under an unrelenting desert sun.

The rattle of a snake in the distance, a warning that this desolation may be the last place you ever breathe.

Rattlesnake Flat is remote, sitting as it does nearly smack in the middle of Adams County between Washtucna to the south and Ralston — which is barely more than a grain elevator, a handful of houses and a park — to the north.

And it’s even a little dusty too, to the extent that just about any place in the Columbia Basin is, sitting amid the region’s sprawling wheat fields.

But it’s also the site of San Francisco-based Clearway Energy Group’s latest project, a massive 57-turbine wind farm that will contribute an average of 50 megawatts of clean power for Avista, which serves nearly 400,000 customers across 30,000 square miles in Washington, Idaho and Oregon.

According to Ben Fairbanks, senior director of wind development and strategy for Clearway Energy, Rattlesnake Flat is also one of the best sites in Eastern Washington for a wind farm.

“It’s a good project,” Fairbanks said. “Compared with other areas, the Palouse is a great but challenging topography. There aren’t many other opportunities for wind power in the Palouse.”

Work crews have been busy pouring the giant hexagonal concrete foundation pads for the 57 giant wind turbines that are being scattered across 20,000 acres, burying power cables, hoisting the masts and attaching the huge turbines and blades with a goal of having the wind farm online by the end of 2020.

It’s not the first renewable energy project for Adams County. In 2019, Strata Solar completed a 200-acre, 28-megawatt solar farm near Lind, the nearest town of any consequence to Rattlesnake Flat.

The sun shines bright in Adams County, and the wind blows too — sometimes gently, and sometimes fiercely.

“The Lind area has significant load in the summer,” Fairbanks said. “Summer peaks because of the irrigation load.”

That makes Rattlesnake Flat a good site, Fairbanks said, rising above the surrounding land to catch the wind and close to two substations that are part of Avista’s power grid.

“The landscape gets up into the wind stream,” Fairbanks said. “It’s an ideal combo: unobstructed wind, ease of construction and access to transmission.”

Clearway Energy will recoup the cost of the $230 million project through a 20-year power purchase agreement with Avista.

Fairbanks said that while the wind farm will produce an average of 50 megawatts, the combination of 47 2.9-megawatt and 10 2.415-megawatt turbines will be capable of producing nearly 160 megawatts of power on a good day.

That’s enough power for a town of around 37,000 people, according to Avista.

However, Avista is only capable of accepting 144 megawatts of power into its grid in that part of Adams County. And not all turbines will be working all the time either, Fairbanks said.

The turbines are not placed randomly, Fairbanks said. Clearway’s engineers studied the wind pattern at Rattlesnake Flat for years prior to beginning construction to optimize the placement of each turbine and minimize the effects on other turbines of the wake each turbine creates when it spins.

Each turbine can rotate 360 degrees, and the blades themselves can also rotate — a process called feathering — to best capture the wind. Each windmill should reach its optimal capacity when the wind is blowing at around 12 miles per hour, Fairbanks said.

“It’s different for every location,” he said. “Each turbine has a power curve.”

In addition, each of the 57 turbines at Rattlesnake Flat will be inspected and maintained once a month, meaning the generator has to be stopped and the turbine blades locked down to keep work crews safe.

All of the turbines will be connected to a data center that monitors how effectively each is working, allowing Clearway crews to make adjustments based on the direction and speed of the wind, Fairbanks said. In addition, Fairbanks said, eight to 12 workers will live within 30-40 minutes of the site in order to keep the windmills maintained and running.

Scott Kinney, the director of power supply for Avista, said the Rattlesnake Flat wind project and the solar farm are part of the company’s long-term goal of having 100 percent clean power generation (including hydropower) by 2045.

Currently, 55 percent of the company’s power comes from renewable, non-carbon emitting sources, Kinney said.

“The solar farm has performed really well for us,” Kinney said. “It has been a reliable project for us.”

Kinney said Avista selected the Rattlesnake Flat project out of 50 or so submitted to the company because it was in the company’s service area and helped the company meet its eventual goal of being carbon-free while keeping the power distribution system reliable without having a “significant rate impact.”

“This is a transition, and we’re cleaning up that last 45 percent of our portfolio,” he said.

Avista is looking to expand its renewable power generation still further, and is asking companies like Strata Solar and Clearway Energy to submit another round of proposals for evaluation.

But whether this next site would also be located in Adams County is anyone’s guess.

“We’re working through those proposals, and we’re hopeful,” Kinney said. “But we can’t guarantee anything. We’ll see how it plays.”

Charles H. Featherstone can be reached at cfeatherstone@columbiabasinherald.com