Yakima County's second large-scale solar facility is online

Roughly 3 1/2 years after his predecessor approved it, Washington Gov. Bob Ferguson was among 50 people celebrating in a remote corner of Yakima County as the Ostrea Solar project went online.

A ribbon cutting ceremony for the 80-megawatt solar farm about 20 miles east of Moxee was hosted Wednesday by its developer, owner and operator, Cypress Creek Energy, with Ferguson joined by state Energy Facility Site Evaluation Council members and other officials.

All stressed Ostrea’s ability to provide much-needed green energy to a regional electrical grid supplying an increasing amount of power to Washington businesses and homes.

“Washington’s economy is growing, and that growth requires more electricity,” said Mike Discenza, Cypress Creek Energy’s chief financial officer, who stood in for company CEO Kevin Smith at the ceremony.

“Ostrea shows how we can responsibly bring new power online quickly and affordably, while creating lasting benefits for the communities where we operate, and caring for the land for generations to come,” he added.

Ferguson, who earlier in the day attended a groundbreaking ceremony for a Tri-Cities area nuclear fusion facility, said developers seeking to build in Washington are constantly asking him and other state officials about the energy supply.

“We need significantly more power online, and this (Ostrea project) is part of that,” Ferguson said. “Obviously there’s no single solution — we need contributions from hydroelectric, solar, wind, even fusion.”

Where the power will go

Discenza noted that Ostrea represents roughly $180 million in private capital investment, and is expected to generate $13.3 million in state and local tax revenue over its operating life of up to 40 years. It is the second large-scale solar operation in Yakima County, located about 13 miles east of the Goose Prairie Solar facility on State Route 24.

He and Ferguson said the project comes online at a time of significant economic and electricity demand growth in Washington. The state led the nation in economic growth during the first quarter of 2026, with real GDP growing at an annualized rate of 4.5%, more than twice the national rate.

The information sector was the leading contributor to that growth, underscoring the increasingly important connection between Washington’s technology-driven economy and the infrastructure needed to power it, Discenza said.

The power generated by the Ostrea solar project will go to Microsoft under a purchase agreement, he added.

Ostrea was approved, along with the similarly-sized and adjacent High Top solar project, by Gov. Jay Inslee in April 2023. Inslee announced his approval in Yakima following a lengthy review and public comment process by EFSEC, the state’s clearing house for solar, wind and other proposed energy facilities in Washington.

Discenza said the development of High Top, immediately west of Ostrea, is dependent upon Cypress Creek’s ability to find a buyer for the power it would produce.

He said there could be an update on High Top and its timeline for development within the next six months to a year.

The Yakima Valley’s famously abundant sunshine was among the reasons California-based Cypress Creek chose the area for the two projects.

“There were three main reasons: the availability of the resource — the sun — the availability of the land and the availability of a transmission line,” Discenza said, referring to the Bonneville Power Administration’s Moxee to Midway 115 kV transmission line that runs adjacent to the project and along SR 24.

Environmental concerns

Discenza, Cypress Creek Regional Manager Andrew Poulson and the company’s Senior Director of Community Affairs Stacy Gramazio all spoke Wednesday about the environmental stewardship that accompanied development of Ostrea.

Consideration of the company’s responsibility to the land began as Cypress Creek worked closely with EFSEC and the Washington Department of Fish and Wildlife during development, Gramazio said, including modifying the design to conserve approximately 275 acres of critical shrub steppe habitat.

Shrub steppe is one of Washington’s most diverse ecosystems, she said, providing habitat for species found nowhere else in the state. It is also increasingly scarce, with an estimated 80% of Washington’s historic shrub steppe lost or degraded to development and agriculture.

Ostrea was designed with wildlife corridors to maintain migratory pathways, including for Rocky Mountain elk that move through the region.

For this reason, the banks of solar panels and other electric infrastructure take up only 10% of the land in the Ostrea Solar site footprint, Gramazio said.

The rest remains vegetation, with sheep grazing a possibility in the future, she added.

In addition, portions of the project site include degraded former cropland that has not been actively farmed for more than 25 years and where invasive and non-native plant species had become established. During construction, invasive plants that can threaten native habitats were removed, and disturbed areas were revegetated.

Gramazio said the project was then seeded with carefully selected mixes of grasses and pollinator-friendly flowering plants. Beneath and around the solar arrays, lower-growing species were selected to establish healthy vegetation without interfering with the panels.

Other restored areas include taller grasses and flowering species that provide additional habitat and forage for pollinators.

Poulson, who was born and raised in Central Washington, attended Wednesday’s ceremony with his wife, Ashley, and their two daughters. The Ellensburg resident said completing construction of Ostrea is also the beginning of Cypress Creek’s long-term responsibility to the land.

“When I tell you we’re going to take good care of this place, I’m speaking not just as someone from the company, but as someone from the community,” Poulson added.

Cypress Creek hopes to preserve the Ostrea site’s potential for agriculture or whatever use future generations determine is best, Discenza said, after its time as a solar power facility is over.

“We are really committed to the long-term ownership model and keeping our commitments to the state and to the county over the next 30-plus years,” he added.