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Explore databasesCalifornia now hosts more than 45 GW of solar capacity—so much that on a mild spring afternoon, wholesale power prices can dip below zero. The state’s combination of strong insolation, ambitious renewable mandates (60% by 2030, 100% zero-carbon by 2045), and a deep project queue has made solar farms in California the centerpiece of US utility-scale solar development. This article maps the ten largest operating installations, the pipeline of projects still to come, and the developers shaping the landscape.
Largest Operating Utility-Scale Solar Installations
As of early 2026, every plant on the top-ten list uses photovoltaic technology except one—Ivanpah, the last large-scale concentrating solar power facility still generating.
Top Ten at a Glance
| Project Name | Capacity (MW) | Technology | County | Key Developer / Asset Owner | Commissioning | Noteworthy Detail |
|---|---|---|---|---|---|---|
| Edwards Sanborn Solar + Storage | 1,200 (solar) + 3,287 MWh storage | PV + BESS | Kern | Clearway Energy Group | 2023–2025 | World’s largest solar-plus-storage complex |
| Mount Signal Solar | 794 | PV | Imperial | Avantus / D. E. Shaw Renewable Investments | 2014–2021 | ~2,000 GWh annual generation |
| Solar Star | 579 | PV | Kern / Los Angeles | SunPower / BHE Renewables | 2015 | Annual output 1,660 GWh |
| Topaz Solar Farm | 550 | PV | San Luis Obispo | First Solar / BHE Renewables | 2014 | 6,200 acres; 1,096 GWh/year |
| Desert Sunlight Solar Farm | 550 | PV | Riverside | First Solar / NextEra Energy Resources & GE Energy Financial Services | 2015 | 3,800 acres; ~1,100 GWh/year |
| Ivanpah Solar Electric Generating System | 392 | CSP (power tower) | San Bernardino | BrightSource Energy / NRG Energy | 2014 | 173,500 heliostats; retiring mid-2026 |
| McCoy Solar Energy Project | 250 | PV | Riverside | NextEra Energy Resources | 2016 | 2,300-acre site |
| Genesis Solar Energy Project | 250 | PV | Riverside | NextEra Energy Resources | 2014 | Pure PV, no storage |
| California Valley Solar Ranch | 250 | PV | San Luis Obispo | SunPower / NRG Energy | 2013 | 735 GWh/year |
| Antelope Valley Solar Ranch One | 230 | PV | Los Angeles | First Solar / Exelon | 2014 | Supplies PG&E under 25-year PPA |
Edwards Sanborn: A Storage-Integrated Milestone
Edwards Sanborn’s 1,200 MW of PV paired with 3,287 MWh of battery storage makes it the highest-capacity solar facility in California—and the largest solar-plus-storage project worldwide. Sited in Kern County, the complex demonstrates how coupling generation with four-hour-duration batteries can smooth delivery into the late afternoon and evening net-peak window.
Ivanpah: The End of an Era for CSP
Ivanpah’s three 459-foot towers and 173,500 heliostats once symbolized the promise of dispatchable solar thermal power. Yet a net capacity factor hovering around 20%, levelized costs far above today’s PV benchmarks, persistent glare complaints, and documented avian mortality—thousands of bird deaths annually—drew intense regulatory scrutiny. PG&E ended its power purchase agreement, and owners BrightSource and NRG confirmed the plant will cease operations by mid‑2026. Its closure marks the first decommissioning of a major utility-scale solar thermal asset in the United States.
What’s Coming Next? California’s Solar Pipeline
Beyond the operating fleet, a pipeline of roughly 20 GW waits—projects under construction, in permitting, or queued for interconnection. Combined with the 45 GW already online (of which utility-scale exceeds 30 GW), California’s total solar commitment is unmatched by any other state.
Near-Term Additions and the 2026 Outlook
Developers expect about 6 GW of new utility-scale solar to come online in 2026 alone, with an additional 14 GW advancing through CAISO interconnection studies and environmental review. Much of this wave is paired with battery storage, a direct response to afternoon ramping needs and the decline of natural gas peaker plants. SB 100’s zero-carbon electricity target for 2045 continues to pull the queue forward, even as transmission constraints and permitting timelines determine which projects break ground first.
How Interconnection Queues Shape the Build-Out
If you are evaluating project viability, start with the CAISO interconnection queue. A project’s queue position often dictates its commercial operation date more than any other factor. A common misstep is assuming that a signed power purchase agreement guarantees on-time delivery; many projects face multi-year delays from cluster study bottlenecks and network upgrade costs that can erode project economics.
How Do PV and CSP Technologies Compare?
More than 95% of California’s utility-scale solar capacity is flat-panel photovoltaic, mostly on single-axis trackers. Concentrated solar power barely exceeds 1 GW—and Ifthe lion’s share comes from Ivanpah alone.
PV’s Dominance: Trackers, Capacity Factors, and Costs
Modern single-axis tracking PV arrays routinely achieve capacity factors of 25–32% in California’s high-irradiance regions. Module efficiency gains and steep declines in inverter and racking costs have driven recent power purchase agreement prices below $30/MWh for new large-scale facilities. These economics favor PV over thermal solar in almost every site assessment.
The Rise and Fall of Concentrated Solar Power at Ivanpah
Ivanpah’s levelized cost of energy sprawled well above $200/MWh under legacy contracts, while comparable PV PPAs now fall below $30/MWh. The missing piece for many CSP plants was cost-competitive thermal storage: unlike later projects that used molten salt, Ivanpah’s direct-steam design offered no built-in storage capability. Soiling on heliostats and lower-than-expected direct normal irradiance further undercut its output. When PG&E terminated the offtake agreement in 2025, plant owners had no path to economic viability without a new, far more expensive contract.
Key Developers and Asset Owners
Concentration among a handful of developers and long-term holders defines the California solar landscape.
Portfolio Snapshot
| Developer / Asset Owner | Notable California Assets | Approximate Installed Capacity |
|---|---|---|
| Clearway Energy Group | Edwards Sanborn (1.2 GW + storage) | >2.5 GW |
| NextEra Energy Resources | Desert Sunlight, McCoy, Genesis | ~1.75 GW |
| BHE Renewables (Berkshire Hathaway) | Solar Star, Topaz | 1,129 MW |
| D. E. Shaw Renewable Investments | Mount Signal Solar (794 MW) | ~800 MW |
| NRG Energy | Ivanpah (minority, retiring), California Valley Solar Ranch | ~640 MW (operating) |
| First Solar (developer; equity sold) | Desert Sunlight, Topaz, Antelope Valley Solar Ranch One | — |
Clearway Energy Group’s California operating portfolio now exceeds 2.5 GW, anchored by Edwards Sanborn—the largest single investment in its fleet. NextEra holds a roughly 1.75 GW footprint that includes the 550 MW Desert Sunlight plant and two 250 MW Riverside County projects, with more solar-plus-storage capacity advancing through its development pipeline. BHE Renewables owns both the 579 MW Solar Star and 550 MW Topaz installations, assets originally developed by First Solar. First Solar, a firm whose thin-film modules and early project development fueled much of the state’s build-out, later divested its equity stakes in those facilities to asset owners. BrightSource Energy, the technology provider behind Ivanpah, will see its 392 MW stake go dark this year as the CSP chapter closes. Avantus (formerly 8minutenergy) developed the 794 MW Mount Signal Solar, now owned by D. E. Shaw Renewable Investments; it remains one of North America’s largest single-site PV plants.
How to Assess Developer Track Records
A common oversight when evaluating developer claims is focusing purely on megawatts installed while ignoring operational metrics like realized capacity factors, curtailment rates, and commissioning delays. Investors and offtakers—including community choice aggregators—increasingly weigh weather-adjusted performance data and asset management history before signing new PPAs. If a developer cannot present at least three years of audited production data from a similar-tier site, treat capacity pledges with caution.
What Are the Economic and Environmental Considerations?
Utility-scale solar brings billions in private investment but also forces hard choices around land, water, and long-term decommissioning.
PPA Pricing and Revenue Stability
Most large solar farms in California earn revenue through long-term power purchase agreements with large investor-owned utilities and community choice aggregators. Recent utility-scale PV contracts have dipped below $30/MWh, a level that can still yield stable returns when paired with a creditworthy offtaker and high insolation. In contrast, Ivanpah’s legacy CSP PPA exceeded $200/MWh—an unsustainable cost that led to contract termination. For a project to be bankable in today’s market, developers typically need a PPA rate above $25/MWh and a term of at least 15 years to cover upfront capital.
Land, Water, and Wildlife Trade-Offs
Scaling solar to tens of gigawatts inevitably transforms thousands of acres of desert habitat. Multi-thousand-acre installations fragment ecosystems, and dust soiling on panels forces operators to choose between frequent water-based cleaning and lost energy output. Glare from arrays—and particularly from Ivanpah’s mirrors—has provoked local opposition. Avian mortality at the concentrating plant drew federal and state regulatory pressure, with peer-reviewed studies documenting thousands of bird deaths annually. A key nuance: while PV arrays also affect birds, the impact comes mainly from habitat displacement, not direct mortality from concentrated solar flux.
End-of-Life and Decommissioning
As the first wave of 2010-era PV plants reaches end-of-life, California faces a new waste stream—millions of panels that will need recycling or safe disposal. Most decommissioning plans are still in early stages, and regulators are beginning to require financial assurances to ensure site restoration. The upcoming Ivanpah dismantling will serve as a benchmark for how the state handles large-scale solar retirement.
Frequently Asked Questions
Where is the largest solar farm in California?
The Edwards Sanborn Solar + Storage facility in Kern County is the largest, with 1,200 MW of PV and 3,287 MWh of battery storage. Among plants without storage, Mount Signal Solar in Imperial County leads at 794 MW.
What are the biggest issues with solar farms?
Land-use conflicts and desert habitat fragmentation top the list, followed by dust soiling, glare, and avian mortality at concentrating plants. Intermittency requires grid balancing, and end-of-life module disposal is emerging as a major waste-management challenge. High operating costs forced the Ivanpah CSP plant to announce retirement.
Are solar farms profitable in California?
Profitability hinges on long-term PPA terms. Many PV projects achieve stable returns thanks to high insolation and low operating costs, but declining PPA prices and upfront capital can squeeze margins. The Ivanpah facility, burdened by an above-market contract that was canceled, proved unsustainable.
Is California closing a solar farm?
Yes. The 392 MW Ivanpah Solar Electric Generating System will shut down by mid-2026 after PG&E terminated its power purchase agreement. It will be the first major utility-scale solar thermal retirement in the US.
How many solar farms are in California?
The state has more than 700 utility-scale solar projects, representing over 30 GW of capacity. Thousands of distributed-generation systems on rooftops and behind-the-meter installations push total solar capacity past 45 GW.
