Lake County hears update on Poe Mountain “FLASHES” pumped-hydro microgrid project

Ben Rickleman, deputy county administrative officer, told the Lake County Board of Supervisors on an informational item that county staff and Trane are advancing a project known as FLASHES — “fire main linked auxiliary supply hydraulic energy storage” — centered on Poe Mountain.

Michael Day, Advanced Energy Project Development Leader at Trane, described FLASHES as a “super closed loop pump storage hydro” system paired with solar that would generate, store and release electricity and also serve as a firefighting water resource. “FLASHES is fire main linked auxiliary supply hydraulic energy storage,” Day said.

The project design presented to the board includes 30 megawatts of solar photovoltaic sited on county land at the Northwest Wastewater Treatment Plant, three 10-megawatt Pelton-wheel hydro turbines (30 MW total) and roofed upper and lower storage tanks to minimize evaporation and speed federal permitting. Day said the system would be configured to provide roughly 20 megawatts to the Lucerne substation and 10 megawatts to the Hartley substation, enabling microgrid coverage for substantial portions of North Lake County, including Lucerne and parts of North Lakeport.

Day said the FLASHES site could supply about 90,000,000 gallons of water stored roughly 800 feet above Highway 29 for firefighting uses, including sprinkler systems over about one…