A huge solar array could be in place by next spring in the hills overlooking Lake Sonoma under a cooperative venture announced Monday between the U.S. Army Corps of Engineers and the Dry Creek Band of Pomo Indians.
The solar panels would generate electricity for the fish hatchery, visitors center and other buildings at the base of Warm Springs Dam northwest of Healdsburg, as well as the tribe’s River Rock Casino and its other facilities near Geyserville, according to details released by the tribe and the Army Corps.
Tribal Chairman Harvey Hopkins called it “great for the tribe, great for Sonoma County and great for the environment.”
The initial 5-megawatt system would be the largest single solar installation in Sonoma County, eclipsing a 3-megawatt facility near Cloverdale.
Army Corps Lt. Col. John Morrow said the solar development is consistent with President Barack Obama’s order for federal agencies to reduce their carbon footprint, along with the corps’ goal of having 25 percent renewable energy by 2025.
Army Corps park rangers took reporters on a tour of the solar site, on a dirt road accessed by four-wheel-drive vehicles.
“There’s plenty of room to expand up here, plenty of sun,” park ranger Brian Emmons said as he overlooked the site, on a tabletop mountain about 500 feet above Lake Sonoma.
The approximately $21 million project will funded by private investors at “zero cost” to the tribe and the corps, according to Rinaldo Veseliza, an architect and engineer with Alisto Group Engineering, the tribe’s energy consultant.
The agreement signed Monday included an easement with the Army Corps that allows the tribe to access the property and explore development of the solar array, tribal attorney Michelle LaPena said.
“The Corps is not in a business of developing solar enterprise,” she said. “But the tribe is able to maneuver on a governmental basis, reach out to developers and industry in the solar and renewable energy fields and bring those experts here.”
The cost of solar energy has gone down significantly over the past decade and is going down further as more companies and investors get involved, Veseliza said.
Investors will benefit from solar tax credits, and the tribe and Army Corps will be able to buy electricity at below-market rates after the solar installation is built, according to Veseliza.
Initially the plan is to have an array with hundreds of panels generating 5 megawatts, the equivalent of enough electricity to supply about 2,500 homes, he said.
The first phase is planned for 42 acres on a now flattened mountaintop that was dug out for 30 million cubic yards of dirt to build Warm Springs Dam. The compacted, earthen-fill dam was completed in 1983.
The dam helps with flood control and stores supplies that provide the bulk of water for 600,000 Sonoma County Water Agency customers in Sonoma and parts of Marin counties.
A second solar construction phase is planned that could bring the total electricity generated to as much as 10 megawatts, with an additional 200 acres made available.
The flat terrain makes it “ideal for this type of venture,” said Mike Dillabough, chief of the Army Corps’ Operations and Readiness Division for the San Francisco District.
“There’s not a lot of other uses for that area. But it’s potentially perfect for the placement of these solar panels to be able to tap in and plug into the grid and put the energy into the system,” LaPena said.