Virginia Solar Panel Performance Benchmarks
Last updated: 2026-04-08 · Solar Benchmark
Virginia Solar Panel Performance Benchmarks
A 6kW solar system in Virginia produces between 8,220 and 8,580 kWh per year depending on location. The Richmond area averages about 8,400 kWh for a 6kW system. Virginia Beach and the Norfolk coastal corridor run slightly higher at around 8,580 kWh. Northern Virginia near the DC metro produces about 8,160 kWh, modestly lower due to urban haze and slightly higher latitude. The Blue Ridge mountain corridor near Roanoke averages about 8,220 kWh.
Monthly Production Benchmarks: Virginia 6kW Reference System
Expected monthly production for a south-facing, 30-degree tilt, 6kW system. Derived from pvlib simulation using Open-Meteo ERA5 historical weather data, Richmond as the statewide reference location.
| Month | Expected Production (kWh) | Notes |
|---|---|---|
| January | 400 | Low sun angle, cool and clear |
| February | 520 | Improving day length |
| March | 720 | Strong spring ramp |
| April | 860 | Excellent shoulder month |
| May | 930 | Near-peak |
| June | 940 | Peak production |
| July | 930 | Heat and humidity effect |
| August | 910 | Late summer, still strong |
| September | 780 | Fall transition |
| October | 640 | Seasonal decline |
| November | 470 | Winter approach |
| December | 360 | Lowest month |
| Annual Total | ~8,460 | Richmond-area 6kW reference |
(Source: pvlib physics modeling, Open-Meteo ERA5 weather data)
Annual Benchmarks by System Size and Virginia Region
| System Size | Northern VA / DC Metro | Richmond Metro | Charlottesville | Virginia Beach / Norfolk | Roanoke / Blue Ridge |
|---|---|---|---|---|---|
| 4 kW | 5,440 | 5,600 | 5,560 | 5,720 | 5,480 |
| 6 kW | 8,160 | 8,400 | 8,340 | 8,580 | 8,220 |
| 8 kW | 10,880 | 11,200 | 11,120 | 11,440 | 10,960 |
| 10 kW | 13,600 | 14,000 | 13,900 | 14,300 | 13,700 |
| 12 kW | 16,320 | 16,800 | 16,680 | 17,160 | 16,440 |
Northern VA specific yield: ~1,360 kWh/kW/year. Richmond: ~1,400. Charlottesville: ~1,390. Virginia Beach: ~1,430. Roanoke: ~1,370.
(Source: pvlib physics modeling, Open-Meteo ERA5 weather data, 2015–2024 averages)
Virginia Climate Zones and Performance Ratio Targets
Virginia spans humid subtropical conditions in the east to humid continental conditions in the west. Performance ratios below 0.78 in any Virginia region warrant investigation.
| Climate Zone | Representative Area | Annual Specific Yield | Expected PR Range |
|---|---|---|---|
| Northern VA / DC Suburbs | Arlington, Fairfax, Alexandria, Loudoun | 1,340–1,380 kWh/kW | 0.78–0.86 |
| Tidewater / Coastal | Virginia Beach, Norfolk, Newport News, Hampton | 1,400–1,460 kWh/kW | 0.79–0.87 |
| Central Piedmont | Richmond, Fredericksburg, Charlottesville | 1,370–1,420 kWh/kW | 0.78–0.86 |
| Valley and Ridge / Blue Ridge | Roanoke, Lynchburg, Staunton | 1,340–1,400 kWh/kW | 0.77–0.85 |
Learn more about how these benchmarks are calculated at /resources/methodology.
What Affects Virginia Solar Output
- Blue Ridge cloud cover: The mountain counties along the Blue Ridge create localized orographic cloud formation, especially in afternoon hours. Roanoke and Lynchburg systems see slightly more summer cloud cover than Richmond despite similar latitudes. The effect is modest, roughly 2–4% annually, but it is real and consistent year over year.
- DC metro heat island: Northern Virginia sits within the Washington DC urban heat island. Urban surfaces retain heat, raising ambient temperatures during summer and increasing panel operating temperatures. The net effect suppresses peak summer output by 1–3% compared to rural locations at the same latitude. This is separate from any shading or soiling issue.
- Coastal irradiance advantage: Virginia Beach and the Hampton Roads area benefit from lower aerosol loading near the coast and slightly higher solar radiation than inland Piedmont locations. The advantage is modest at about 2–3% annually but is consistently visible in ERA5 data.
- Summer humidity: Virginia's June through September period brings high dewpoint temperatures, particularly in the Tidewater region. Humid air scatters some direct beam radiation into diffuse. This slightly reduces the peak-hour direct irradiance that fixed-tilt systems capture most efficiently.
- Net metering and policy: Virginia passed the Virginia Clean Economy Act with mandatory net metering and an ambitious 100% clean energy target by 2045. The State Corporation Commission regulates utility solar rates. Policy stability is a meaningful factor in long-term financial modeling for Virginia systems.
Frequently Asked Questions
Q: What should a 6kW solar system produce per month in Richmond?
A: The Richmond benchmark averages about 705 kWh/month. June is the peak at roughly 940 kWh; December is the lowest at 360 kWh. Consistent summer production below 800 kWh/month (June-August) on a 6kW system in Richmond suggests a problem worth investigating.
Q: Is Virginia Beach better for solar than Northern Virginia?
A: Virginia Beach systems average about 8,580 kWh/year for 6kW versus 8,160 kWh/year in Northern VA. The 5% difference reflects higher coastal irradiance and less urban heat-island suppression. Both locations have strong financial cases for solar given Virginia's net metering policy.
Q: Why does my Roanoke system produce less than a Richmond system?
A: Roanoke averages about 8,220 kWh/year for 6kW versus 8,400 kWh/year in Richmond. The modest gap reflects orographic cloud formation from the surrounding Blue Ridge terrain. A Roanoke system at its regional benchmark is healthy.
Q: How do I get an independent benchmark for my Virginia solar system?
A: A valid benchmark requires production data and actual hourly weather at your address. ERA5 data captures the year-to-year weather variation that generic statewide averages miss. The difference between a Northern VA and Virginia Beach benchmark matters for accurate diagnosis. Learn more at /resources/methodology.
Data: pvlib physics modeling + Open-Meteo ERA5 weather data | Last updated: 2026-04-08 | Solar Benchmark