California has built the West's largest solar and battery fleet, but the state is not a solved clean-energy story. Gas still supplies a large annual block, hydro swings with weather, Diablo Canyon remains a firm clean anchor, and geothermal gives the state another strategic resource beyond solar and batteries.
The state has moved from gas dominance toward a much larger clean portfolio. Solar is the fastest structural change, hydro remains variable, and nuclear and geothermal keep firm clean resources in the mix.
Utility-scale solar supplied about 55.6 TWh in 2025, but gas was still the largest single line. Hydro, nuclear, wind, and geothermal together make California's clean supply broader than a solar-only frame would suggest.
California's 15.2 GW operating battery fleet is the Western benchmark. The next question is how that fleet changes evening reliability, gas operations, imports, curtailment, and the value of nearby states' solar, storage, geothermal, and transmission.
The May 2026 EIA 860M generator workbook shows 15.2 GW of operating battery capacity in California and another 10.2 GW in the planned battery pipeline. That puts California in a different category from the rest of the Western state set.
Through April, California utility-scale solar is above the same 2025 period, gas is down sharply, nuclear is higher, hydro is lower, and coal remains a near-zero state-level line.
The first California page should use a short project table rather than an exhaustive list. The strongest current signal is the scale of hybrid solar-plus-storage and standalone battery rows in the May 2026 workbook.
| Project | Technology | Capacity | Status | Timing | Why it matters |
|---|---|---|---|---|---|
| Bellefield 2 Solar & Energy Storage Farm | Solar + battery | 500 MW solar + 500 MW battery | Under construction | 2026 planned | A large Kern County hybrid project that fits California's next-stage solar-plus-storage buildout. |
| Grace Energy Center | Solar + battery | 500 MW solar + 500 MW battery | Regulatory approvals received | 2027 planned | A major approved hybrid row in the May 2026 generator workbook. |
| Darden solar and battery phases | Solar + battery | 1,371 MW solar + 1,215 MW battery | Regulatory approvals received | 2028 planned | A cluster large enough to matter for the next California page revision. |
| Easley Solar | Solar + battery | 290 MW solar + 350 MW battery | Late-stage / approved rows | 2026-2028 planned | Useful example of the near-term hybrid pipeline rather than a pure solar story. |
| Nighthawk Energy Storage | Battery storage | 300 MW | Under construction | June 2026 planned | Standalone storage remains part of California's pipeline even as hybrid projects dominate the public story. |
| Item | Role | Status | Interpretation |
|---|---|---|---|
| Operating batteries | Flexibility | 15,174 MW operating, May 2026 | California remains the Western storage benchmark by a wide margin. |
| Planned batteries | Pipeline | 10,241 MW planned, May 2026 | The pipeline is still large even after several years of rapid operating growth. |
| Diablo Canyon | Firm clean power | 2,323 MW operating in EIA 860M | Nuclear keeps California from being a solar-storage-only story. |
| Geothermal fleet | Firm renewable power | 2,936 MW operating, May 2026 | California and Nevada are the strongest geothermal states in the current Western page set. |
| Hydro variability | Weather-sensitive supply | 27,855 GWh in 2025 | Hydro swings materially across years, which changes how gas and imports should be interpreted. |