Seattle company proposes new solar farm near Tri-Cities. It could be the county’s 6th

A Seattle company is proposing a solar farm south of the Tri-Cities that could generate power each year for about 13,000 homes.

Wallula Gap Solar is the fourth solar project in Benton County now seeking a permit to build through the Washington state Energy Facility Site Evaluation Council, or EFSEC.

One Energy Renewables already is building Goose Prairie Solar, an 80-megawatt capacity project east of Moxee in Yakima County. It was approved two years ago by Gov. Jay Inslee on the recommendation of the site evaluation council.

Wallula Gap Solar would be a 60-megawatt solar farm, possibly with 240 megawatts of battery storage, on nearly 440 acres just north of the Columbia River.

The site is about 25 miles south of Tri-Cities, off Highway 14 about five miles west off Interstate 82, northwest of Plymouth and east of Paterson.

The developed area of the project would cover about 390 acres.

The project annual output is 137,700 megawatt hours or enough to power about 13,000 average homes, according to One Energy Renewables.

The land to be leased is flat and was previously irrigated farmland, but owner Farmland Reserve has moved its irrigation to more productive land, said Nathan Stottler, the One Energy Renewables associate director for development, at an EFSEC meeting.

Farmland Reserve is the parent company of Kennewick-based AgriNorthwest and the investment arm of the Church of Jesus Christ of Latter Day Saints.

Stottler said the land is level, but fairly rocky, and has few nearby neighbors.

One Energy Renewables is in early discussions with a sheep grazer to use the land for grazing in addition to energy production.

It also is working out agreements with Benton PUD and the Bonneville Power Administration for transmission of electricity.

If battery storage is included in the project, lithium-ion batteries would be in a series of modular containers.

The project could be producing electricity as soon as late 2026.

One Energy Renewables estimated an average of 56 workers during construction and five part-time employees during its proposed 35 years of operation.

EFSEC also is considering a recommendation to Inslee on the Hop Hill Solar and Storage Project 11 miles north of Prosser and seven miles east of the Highway 241 and Highway 82 intersection near the Hanford nuclear site. It could produce up to 500 megawatts of solar energy power and also could use battery storage.

About five miles north of that is the proposed Wautoma Solar Project, a 470-megawatt solar generation project coupled with a four-hour battery energy system, on the Benton County line with Yakima County.

Those two projects and the proposed Wallula Gap project are on Growth Management Act agricultural land, and the Benton County Commission voted in late 2021 to protect farmland by restricting new wind and solar projects to industrial zones. Previously, they were allowed in agriculture and small rural acreage areas.

All three projects chose to file for a state permit rather than for county approval after the zoning restriction was approved.

The Washington governor, upon recommendation from EFSEC, may preempt land use plans and zoning regulations to authorize an energy project.

The Horse Heaven Wind Project, which would stretch from south of Kennewick to south of Benton City along the Horse Heaven Hills ridgeline, also is proposed to include solar production and battery energy storage. Its proposal was made before the Benton County zoning restriction.

Benton County has opposed the Wautoma and Hop Hill solar projects and the Horse Heaven project.

Energy Northwest already operates the White Bluffs Solar Station 10 miles north of Richland and the Horn Rapids Solar, Storage and Training Project.