WATCH: State Supreme Court hears landmark case on massive Tri-Cities wind, solar farm

Scout Clean Energy, of Boulder, Colorado, initially submitted an application in 2021 for a project that could be up to 244 wind turbines, each about 500-feet tall, and three solar arrays.

Debate over how large the project would be and community and tribal concerns has progressed in hearings and legal filings over the last few years.

Tri Cities CARES, Benton County and the Yakama Nation filed separate petitions seeking to overturn the final decision on the scope of the project. Those cases were combined and arguments took place Thursday at the Temple of Justice in Olympia.

“The unanimous council [EFSEC] determined that mitigation, serious mitigations to protect tribal interests, visual interests of the 300,000 people in the Tri Cities should be imposed,” said Richard Arambaru, attorney for Tri Cities CARES.

“EFSEC concluded there were significant impacts on the community. That it would not kill the project, but it would take out those parts of the project that so interfered with the rights of the public, and with the rights of the Yakama nation.”

Arambaru was referring to EFSEC initially approving a reduced number of turbines in April 2024 to create necessary protected buffer zones for ferruginous hawk nests and take tribal concerns into consideration.

However, Inslee pushed to maintain the project for up to 222 turbines, as well as solar panel arrays and battery storage facilities, and the current form of the project is much like the original large scale plan.

Arambaru told the court EFSEC did its due diligence, but Inslee overruled, without the authority to do so.

“They spent eight days, 2,000 pages of transcript, 34 witnesses during the course of the administrative hearing. When it gets to the governor who for all we know never even visited the project, never listened to a word of the transcript, the governor did not follow that decision.”

Former Washington Supreme Court Justice Phil Talmadge argued on behalf of the developer, Scout Clean Energy.

“The process that was undertaken worked as the legislature envisioned it. The opponents of this project are not here to improve it. They are here to kill it,” said Talmadge.

He told the justices opponents are hoping that having the Trump administration on their side will halt the project.

“The Trump administration is proposing to end significant tax credits for renewable energy projects. They hope to use that as a tool to defeat this project," Talmadge said.

Talmadge argued the hearing process was fair in considering all parties over several years.

“The hearing process was robust to say the least. 64,000 pages of record. We’re not talking about something that was done superficially here.”

Shona Voelckers, attorney for the Yakama Nation, one of the plaintiffs in the case, told the court EFSEC failed in balancing the state’s energy needs against environmental harms and tribal concerns. 

“It is the largest wind, solar and battery storage project ever proposed in the state,” said Voelckers, who noted the council had a responsibility to heavily weigh tribal impacts. “And to get specific special consideration of impact to overburdened communities including the Yakama Nation. That did not happen here.”