Rancho Penasquitos is retired. EIA's monthly generator inventory (EIA-860M, August 2026) lists every generator at this hydroelectric plant as retired; the last one retired in October 2022. It is not counted among California's operating plants or in any ranking on this site.
EIA also lists 1 planned generator at this plant (4.3 MW nameplate): a proposed project, not yet operating.
The figures below describe the plant when it ran: equipment from EIA Form 860 (2024).
The 4.6 MW is nameplate capacity: the most this plant's generators are rated to produce, not what it actually generates. EPA eGRID reports no positive net generation for it this year.
How it works
Why the numbers look like this: output depends on how far the water falls and how much of it flows, so a hydro plant's year follows rain and snowmelt — and dam operators can hold water back for the hours when power is worth the most.
This plant highlighted in navy-ringed pin; other generators within 25 miles shown as fuel-colored dots.
| Address | 12298 Alemania Road |
|---|---|
| City | San Diego |
| County | San Diego County |
| State | California |
| ZIP | 92129 |
| Coordinates | 32.93695, -117.11367 |
| Operator | San Diego County Water Auth |
| ID | Technology | Fuel | Nameplate capacity | Status | Online |
|---|---|---|---|---|---|
| G100 | Conventional Hydroelectric | Water | 4.6 MW | Retired | 2007 |
| NERC Region | WECC |
|---|---|
| Balancing Authority | California Independent System Operator |
Hydroelectric plants spin turbines using falling or flowing water — typically from a dam-impounded reservoir. They are dispatchable, long-lived, and emission-free at the point of generation, though large reservoirs can disrupt rivers and ecosystems and methane can be released from flooded vegetation.