Solar Farms & Panel Systems in the U.S. — Types, Evolution, and the Biggest Projects
Updated Oct 2025 • Links go to primary sources (SEIA, EIA, LBNL/NREL, BLM, project owners)
Types of Solar Farms & Panel Systems
Utility-scale PV (dominant)
- Fixed-tilt PV: panels set at a fixed angle; lowest capex; used where land is very cheap or winds are high.
- Single-axis trackers: rows pivot east↔west to follow the sun; now standard for most U.S. utility projects; often paired with bifacial modules for extra yield.
- Solar + Storage: co-located batteries shift mid-day solar to evening peaks and improve grid value.
Other configurations
- Community solar: shared arrays customers subscribe to for bill credits.
- Floating PV (FPV): on ponds/reservoirs; helps reduce evaporation and panel temps.
- Agrivoltaics: raised/row-spaced arrays with grazing or crops beneath.
- Concentrating Solar Power (CSP): thermal plants with mirrors; niche in the U.S. today.
Evolution & Tech Trends
- Shift from fixed-tilt to trackers + bifacial for higher capacity factors.
- Rapid rise of PV+storage hybrids to deliver evening power and firming services.
- Module efficiencies and inverter densities keep improving; BOS/software optimizations cut O&M.
- LCOE Utility-scale PV remains the cheapest new-build power in most U.S. regions (see Lazard).
Largest U.S. Solar Farms (MW AC & Approx. Acres)
| Project | State | Capacity (MW AC) | Approx. acres | Notes / Source |
|---|---|---|---|---|
| Topaz Solar Farm | CA | 550 | ~4,700 | BHE fact sheet. |
| Desert Sunlight | CA | 550 | ~3,800 | First Solar/NextEra press. |
| Solar Star | CA | 579 | ~3,200 | EDF/MidAmerican facts. |
| Mount Signal (Imperial Valley) | CA | 614 | ~3,900* | *MS1 ~1,940 ac; MS3 ~2,000 ac. |
| Gemini Solar + Storage | NV | 690 (PV) | ~7,100 | BLM ROD; includes large battery. |
| Copper Mountain Solar | NV | ~802 | ~4,000 | Boulder City complex (est.). |
| Hornet Solar | TX | 600 | ~3,900 | Developer site & news. |
| Frye Solar (Repsol) | TX | 570–637 | n/a | 570 MW operating; 637 MW installed. |
| Hecate Outpost Solar | TX | ~514 | ~18,500 | TX Comptroller filing (project area). |
| Mockingbird Solar Center (Ørsted) | TX | 468–488 | ~4,900 | 953 acres donated to prairie preserve. |
| Fox Squirrel Solar (Amazon) | OH | 577 | ~3,444 | EDF/Enbridge & trade press. |
| Sonoran Solar Energy (ROW) | AZ | ~300 | ~3,320 | BLM right-of-way approval. |
Note: Acres are approximate project areas; panel coverage is a subset and varies by design.
Which states benefit most?
Leaders by capacity: California, Texas, Florida, Arizona, North Carolina, Nevada (see SEIA state dashboards).
Leaders by share of generation: California & Nevada exceeded 30% solar of annual electricity in 2024 (Ember).
Why: strong sun + land availability, proactive policy, and fast-growing storage pairings.
How big is solar now & how fast is it growing?
- U.S. electricity from solar (2024): ~7% of total generation (utility + small-scale).
- Utility-scale added in 2023: ~18.5 GWAC (LBNL). 2024: ~41.4 GWDC (SEIA).
- How many “solar farms”? The USPVDB maps 5,700+ front-of-the-meter PV facilities ≥1 MW through mid-2024.
- Batteries: Utility storage capacity is expanding rapidly; 2025 additions set near-record levels (EIA).
Do solar farms lower people’s electric bills?
- Wholesale: More daytime solar (and batteries) generally pushes down spot prices in sunny regions (e.g., Texas 2024).
- Retail bills: Depend on many non-energy costs (wires, wildfire mitigation, legacy contracts). Rates don’t always fall even when wholesale prices do.
- Community solar: Typical subscriber savings are often on the order of ~10%, varying by state/program.
Bottom line: solar helps at the wholesale level; bill impacts for households vary by market design and fees.
Utility-scale vs. Rooftop: efficiency & environment
- Cost: Utility-scale PV has the lowest LCOE of new-build power in most regions; rooftop costs more per kWh but offsets retail rates.
- Land & siting: Rooftop reuses built space. Utility-scale uses land but can co-locate with grazing, pollinator habitat, or on disturbed lands.
- Carbon: Life-cycle emissions for PV are very low (tens of gCO₂e/kWh) for both rooftop and utility-scale.
- Grid value: Utility-scale with storage improves evening reliability; rooftop reduces local feeder loads and losses.
Can solar power the AI build-out by itself?
AI/data centers are driving a huge new load this decade. Solar + storage will supply a significant share of the added energy, but 24/7 demand and power-density needs mean the U.S. will require a portfolio: solar + batteries, wind, transmission, demand-flexibility, and (in many regions) firm low-carbon resources like hydro, geothermal, or nuclear. Fast-ramping gas may still play a peaking/back-up role while clean firm options scale.
Sources (primary/owner, agencies & labs)
- Largest projects & acres: BLM on Gemini (7,100 acres), BHE/Topaz, Desert Sunlight press, Hornet, Fox Squirrel, Hecate Outpost filing, Mockingbird, BLM on Sonoran Solar ROW.
- Totals, growth, technology: LBNL Utility-Scale Solar 2024, USPVDB (U.S. Large-Scale Solar Database), SEIA 2024 Year-in-Review, EIA Today in Energy.
- State leaders & solar share: SEIA State Dashboards, Ember U.S. Electricity 2025.
- Costs & emissions: Lazard LCOE+ 2025; PV life-cycle GHGs: NREL 2024 LCA.
- AI/data-center demand: IEA 2025 brief.