The 10 Biggest Solar Farms in the US (2026 Edition)

The biggest solar farms in the US now routinely cross the 1 GW mark—Samson Solar Energy Center leads the 2026 ranking at 1,300 MW—and the buildout shows no signs of slowing. Utility-scale installations in the Southwest, California, and Texas anchor state renewable portfolio standards and corporate net‑zero commitments, while battery storage, bifacial modules, and single‑axis trackers have become table stakes for projects entering the interconnection queue. This snapshot covers the top ten operational plants, their key metrics, and what their design tells investors, developers, and supply‑chain analysts about the direction of the US solar market.

Methodology

We cross‑referenced FERC filings, developer disclosures, and independent system operator interconnection records to rank each facility by nameplate capacity in megawatts. Only grid‑connected, utility‑scale projects of 50 MW or greater are included, and every site had achieved commercial operation or first power by 31 December 2025. When a project was built in phases, we report the aggregate commissioned capacity. Annual generation figures and capacity factors are indicative, drawn from public production data and typical performance within each solar resource zone.

The 10 Biggest Solar Farms in the US (2026 Ranking)

The table below provides a side‑by‑side look at the biggest solar farms in the US based on operational capacity. Where a project pairs generation with battery storage, that storage is noted; a dash indicates no on‑site storage co‑location (though grid‑scale storage may be interconnected nearby). After the table, each facility gets a detailed, data‑dense profile.

Rank	Solar Farm	State	Capacity (MW)	Storage (MW)	Year(s) Online	Annual Gen (GWh)	Technology	Primary Off‑taker(s)
1	Samson Solar Energy Center	Texas	1,300	—	2022–2025	3,300	Bifacial, single‑axis tracker	AT&T, Honda, McDonald’s, City of Austin & others
2	Mount Signal Solar	California	794	—	2021	1,900	Monocrystalline, single‑axis tracker	SDG&E, SCE
3	Copper Mountain Solar Facility	Nevada	802	—	2025 (phase 5) / earlier phases	1,900+	Thin‑film (CdTe), tracker	SCPPA
4	Gemini Solar Project	Nevada	690	380	2023	1,800	Bifacial, single‑axis tracker	NV Energy, municipal group
5	Solar Star	California	579	—	2015	1,100	High‑efficiency crystalline, tracker	SCE
6	Topaz Solar Farm	California	550	—	2014	1,050	Thin‑film (CdTe), fixed‑tilt	PG&E
7	Desert Sunlight Solar Farm	California	550	—	2015	1,050	Thin‑film CdTe	PG&E, SCE
8	Alta Solar Project	California	280	—	2025	650	Thin‑film	Community choice aggregator
9	White Wing Ranch Solar	Arizona	250	—	2024	575	Bifacial, single‑axis tracker	Southwestern utility
10	Lone Valley Solar Park I & II	California	200	—	2023	440	Crystalline, single‑axis tracker	SCE

1. Samson Solar Energy Center

• Capacity: 1,300 MW (five phases of 200–300 MW each)
• Location: Lamar, Red River & Franklin counties, Texas
• Footprint: ~18,000 acres
• Technology: Bifacial modules on horizontal single‑axis trackers
• Off‑takers: AT&T, Honda, McDonald’s, the City of Austin, and other utility/commercial buyers under long‑term PPAs
• Annual generation: ~3,300 GWh, making it the largest US plant by both capacity and estimated output

2. Mount Signal Solar

• Capacity: 794 MW (three phases; Mount Signal 3 completed in 2021)
• Location: Imperial County, California (Imperial Valley)
• Footprint: 5,000+ acres
• Technology: Monocrystalline‑silicon modules on single‑axis trackers
• Off‑takers: San Diego Gas & Electric, Southern California Edison
• Annual generation: ~1,900 GWh

3. Copper Mountain Solar Facility

• Capacity: 802 MW (aggregated after Copper Mountain 5 came online in late 2025)
• Location: Boulder City, Nevada
• Technology: Thin‑film modules layered onto earlier phases; single‑axis trackers
• Off‑taker: Southern California Public Power Authority, among others
• Annual generation: Exceeds 1,900 GWh

4. Gemini Solar Project

• Capacity: 690 MW solar + 380 MW battery energy storage
• Location: Clark County, Nevada (BLM‑managed land)
• Footprint: 7,100 acres
• Technology: Bifacial modules on single‑axis trackers; 4‑hour duration battery system
• Off‑takers: 25‑year PPA with NV Energy plus a 10‑year deal with Nevada municipalities
• Annual generation: ~1,800 GWh

5. Solar Star

• Capacity: 579 MW
• Location: Kern & Los Angeles counties, California
• Footprint: ~3,200 acres
• Technology: High‑efficiency crystalline‑silicon modules on single‑axis trackers
• Off‑taker: Southern California Edison
• Annual generation: ~1,100 GWh

6. Topaz Solar Farm

• Capacity: 550 MW
• Location: San Luis Obispo County, California
• Footprint: 4,700 acres
• Technology: Thin‑film (CdTe) modules on fixed‑tilt mounts
• Off‑taker: Pacific Gas & Electric (25‑year PPA)
• Annual generation: ~1,050 GWh

7. Desert Sunlight Solar Farm

• Capacity: 550 MW
• Location: Riverside County, California (federal land)
• Technology: Thin‑film CdTe modules
• Ownership: NextEra Energy Resources / Berkshire Hathaway Energy
• Off‑takers: PG&E, Southern California Edison
• Annual generation: ~1,050 GWh

8. Alta Solar Project

• Capacity: 280 MW
• Location: Fresno County, California
• Footprint: 2,300 acres
• Technology: Thin‑film PV; dedicated 230 kV transmission line into CAISO
• Off‑taker: Community choice aggregator (15‑year PPA)
• Annual generation: ~650 GWh

9. White Wing Ranch Solar

• Capacity: 250 MW
• Location: Yuma County, Arizona
• Footprint: ~2,000 acres
• Technology: Bifacial modules on horizontal single‑axis trackers
• Off‑taker: Southwestern utility under long‑term PPA
• Annual generation: ~575 GWh

10. Lone Valley Solar Park I & II

• Capacity: 200 MW (aggregated)
• Location: Kern County, California
• Footprint: ~1,400 acres
• Technology: Crystalline‑silicon modules, single‑axis trackers
• Off‑taker: Southern California Edison (20‑year PPA)
• Annual generation: ~440 GWh

What Makes These the Biggest Solar Farms in the US?

Beyond raw megawatts, several design and market choices separate the largest solar plants from the rest of the queue. These trends show up across the entire top‑10 list and signal where utility‑scale solar is heading next.

Battery co‑location moves from pilot to prerequisite

Gemini’s 380 MW of storage isn’t a one‑off experiment. The interconnection queues for 2026–2028 are stuffed with hybrid solar‑plus‑storage projects, and independent system operators increasingly favor facilities that can smooth their own output. A plant that pairs generation with 4‑hour batteries can capture peak evening prices and avoid curtailment, improving the project’s net revenue even if the nameplate solar capacity is slightly lower than a pure‑play competitor.

Corporate and municipal offtakers unlock gigawatt scale

Samson’s roster of corporate buyers—AT&T, Honda, McDonald’s—illustrates how long‑term power purchase agreements with creditworthy non‑utility entities can underwrite massive projects. Municipal aggregations (Gemini, Copper Mountain) and community choice aggregators (Alta) further diversify the offtake base, insulating developers from single‑buyer risk and accelerating financial close.

Technology choices directly impact land use and revenue

The divide between fixed‑tilt thin‑film (Topaz, Desert Sunlight) and bifacial‑on‑tracker designs (Samson, Gemini, White Wing) is stark. Bifacial modules on single‑axis trackers typically deliver a 10–15% annual energy gain over monofacial fixed‑tilt at the same capacity. That gain reduces the land area needed per MWh, but it also adds upfront cost. Developers in high‑irradiance areas like the Southwest are increasingly choosing the bifacial‑tracker combination, while fixed‑tilt thin‑film remains viable where land is cheap and module efficiency takes a back seat to capital discipline.

Land nexus drives siting decisions

The biggest solar farms in the US concentrate on private land in Texas and California’s Central Valley, or on Bureau of Land Management parcels in Nevada and Arizona. San Joaquin Valley farmers, for instance, are leaning into solar leases because they lock in 20–30 years of drought‑proof revenue without selling the land. The same dynamic pushes projects onto marginal agricultural ground with high insolation, creating a new asset class for landowners who previously depended on water‑intensive crops.

Practical Insights for Evaluating a Utility‑Scale Solar Plant

Below are a few heuristics that experienced solar investors and due‑diligence teams use to size up a project quickly. None of these replace a full interconnection study, but they surface the factors that separate an average project from the best in class.

• Start with capacity factor, not just megawatts. A 500 MW plant in a cloudy region can generate less energy than a 400 MW plant in the Mojave Desert. Always check the pro‑forma capacity factor and compare it against actual generation data from nearby operating plants.
• Understand curtailment risk before modeling revenue. Even a high‑irradiance site can underperform if the local grid is saturated. Review the interconnection agreement and ISO curtailment reports—projects in West Texas or the Imperial Valley can see meaningful hours of curtailment despite excellent solar resources.
• Scrutinize module and tracker choices. A fixed‑tilt thin‑film installation (like Topaz) behaves very differently from a bifacial‑tracker array (like White Wing Ranch). The technology package changes everything from degradation rates to snow‑shedding performance, so don’t assume that one MW equals one MW.
• Follow the offtaker credit profile. A 20‑year PPA with an investment‑grade utility provides a different risk‑return profile than a contract with a startup community choice aggregator. The Samson model—layering multiple high‑credit corporate offtakers—is often a sign of robust revenue diversification.
• Check the transmission queue early. Interconnection delays are the number‑one reason utility‑scale projects slip schedule. FERC filings show the interconnection position, but actual timelines depend on network upgrades that may not be fully funded—this is where many new entrants get caught.

Conclusion

The 2026 roster of the biggest solar farms in the US confirms a market that is scaling up, smarter and faster. Storage co‑location, bifacial tracking technology, and a diversified offtaker mix are no longer differentiators—they are the baseline for competitive projects. As interconnection queues swell and corporate demand for 24/7 clean energy grows, the next wave of 500‑MW‑plus facilities will have to deliver more than just electrons; they will need to prove they can do it profitably in an increasingly crowded field.