Capacity Factor: Why Rated MW Doesn't Tell the Full Story
A 100 MW solar farm and a 100 MW wind farm sound equivalent — they're not. Capacity factor measures how much of the rated capacity is actually used over a year. U.S. utility-scale solar averages 25–30% capacity factor (100 MW produces 220,000–260,000 MWh/year). Onshore wind averages 30–40% capacity factor (100 MW produces 260,000–350,000 MWh/year). Offshore wind achieves 40–55% (especially in northeastern U.S. waters with consistent strong winds). Both dramatically exceed coal (40–50%) in terms of actual clean energy production per rated MW — but they also require dispatchability solutions (storage, transmission, backup generation) that fossil plants provide inherently.
Levelized Cost of Energy: Both Are Now Among the Cheapest Sources
Lazard's Levelized Cost of Energy Analysis (LCOE, 2024) shows utility-scale solar at $24–$96/MWh and onshore wind at $24–$75/MWh — making both competitive with or cheaper than any new fossil fuel plant. Offshore wind runs $72–$140/MWh due to installation complexity. These costs exclude transmission and integration; adding those brings real-world all-in costs higher, but both remain competitive with natural gas at $39–$101/MWh for new combined-cycle plants. The cost trajectories are also moving in different directions: solar and wind costs have fallen 70–90% since 2010; gas plant economics depend on volatile fuel prices.
Timing of Generation: The Critical Complementarity
Solar generation peaks midday and in summer; wind generation peaks evenings and in winter — in most U.S. regions. This temporal complementarity is why grid operators increasingly view solar-plus-wind combinations as more valuable than either alone. The Pacific Northwest has strong winter hydro; the Southeast has strong summer solar; the Great Plains has strong year-round wind. Grid-level integration of diverse renewable sources across wide geographic areas makes the intermittency problem far more manageable than the simplified "sun doesn't always shine, wind doesn't always blow" framing suggests.
Land Use and Co-Benefits
Utility-scale solar uses 5–10 acres/MW; wind uses 0.25–1.5 acres/MW of actual disturbed land (with farming continuing around turbine bases). Both have dramatically lower land disturbance than coal mining, oil extraction, or natural gas operations when lifecycle land impacts are counted. Solar installations on brownfields, parking lots, and over canals (agrivoltaics) can reduce net land use significantly. Wind turbines in agricultural areas generate lease income for farmers ($5,000–$8,000/turbine/year) while allowing full farming operations between turbines — making wind generation a significant supplemental income source in farm states.
Residential Cost Per Watt: Solar vs. Small Wind Turbines
Homeowners comparing options for their own property face very different economics than the utility-scale numbers above. At residential scale, solar is the clear winner on cost per watt in almost every U.S. location:
| Residential Solar | Residential Small Wind | |
|---|---|---|
| Installed cost per watt | $2.50–$4.00/W | $5.00–$8.00/W (1–10 kW systems) |
| Typical system cost | ~$18,000–$24,000 (7 kW) | ~$35,000–$70,000 (10 kW, incl. tower) |
| Site requirements | Roof or ground with sun exposure | Open land, average wind speed 5.5+ m/s (12+ mph), tower height 80–120 ft |
| Permitting complexity | Building permit + utility interconnection | Zoning variance, setback rules, often FAA review near airports |
| Maintenance | Minimal (occasional cleaning, inverter swap ~15 yrs) | Moving parts — gearbox/bearing service every few years |
The gap is mainly about scale and standardization: solar hardware and installation crews are mass-market, while residential wind turbines are a small, specialized industry with higher per-unit engineering and permitting costs. A home wind turbine only pulls ahead of solar economically on rural properties with strong, consistent wind and little tree cover or shading — otherwise, solar's lower cost per watt and simpler permitting make it the default choice for U.S. homeowners.
Which Should You Choose for Your Home?
Use this quick framework instead of comparing sticker prices alone:
- Suburban or urban lot, decent sun exposure: Solar wins on cost, permitting, and resale value in almost every case.
- Rural property, 1+ acre, average wind speed above ~12 mph, few obstructions: Small wind can be competitive, especially paired with solar in a hybrid system to smooth out day/night and seasonal gaps.
- Heavily shaded lot with no good roof orientation but open land: This is one of the few scenarios where wind alone may outperform solar — check wind resource data for your exact site before committing.
- Uncertain about site wind speed: Don't guess — the NREL Wind Resource Maps and a site-specific anemometer reading (recommended for any wind investment above $10,000) are worth the time before buying a turbine.
Note on tax credits: The 30% federal Residential Clean Energy Credit (Section 25D) covered both home solar and small wind turbines, but it expired for systems placed in service after December 31, 2025 (One Big Beautiful Bill Act, signed July 2025). As of 2026, neither technology receives this federal credit — the cost-per-watt figures above are unsubsidized installed costs. State, utility, or local incentives may still apply; check dsireusa.org for current programs in your area.