Peak Sun Hours in Rhode Island
2026 NREL PVWatts v8 Data
Rhode Island averages 4.7 peak sun hours per day, ranking #34 of 51 US states and DCfor solar potential per NREL's PVWatts v8 model. That puts Rhode Island 6% below the US average of 4.98 PSH.
Monthly Peak Sun Hours in Rhode Island
Rhode Island's solar resource peaks in July at 6.3 peak sun hours per day and bottoms out in December at 2.63. That December figure is the one that matters most for sizing.
What 4.7 Peak Sun Hours Actually Means
A peak sun hour represents one hour of solar irradiance at 1,000 watts per square meter. Rhode Island gets far more daylight hours than 4.7, but the sun isn't always at peak intensity. Peak sun hours compress a full day's variable sunshine into an equivalent number of full-power hours.
In practical terms, 4.7 PSH means a 400W solar panel in Rhode Island produces about 1.41 kWh per day after real-world losses.
Solar Production in Rhode Island
Benchmarks: U.S. avg 4.98 · Phoenix 6.54 (highest) · Seattle 3.95 · Anchorage 3.17 (lowest). Above ~5.5 = sunny · 4.5–5.5 = average · below 4.5 = cloudy.
Tap to see sensitivity analysisSensitivity analysis
| Scenario | Value |
|---|---|
| Low (-20%) | 1.1 kWh |
| Expected | 1.4 kWh |
| High (+20%) | 1.7 kWh |
Your daily production scales linearly with both panel wattage and peak sun hours. A 10% change in either input changes your result by 10%.
Worked Examples for Rhode Island
| System Size | Daily kWh | Monthly kWh | Yearly kWh |
|---|---|---|---|
| 3 kW | 14.1 | 423 | 5,147 |
| 5 kW | 23.5 | 705 | 8,578 |
| 10 kW | 47.0 | 1,410 | 17,155 |
Using Rhode Island's annual average of 4.7 PSH. Winter production drops ~30%; summer runs ~25% higher.
How Rhode Island Compares
The US average is 4.98 PSH per day, so Rhode Island sits 6% below the national average.
| State | Annual PSH | Rank |
|---|---|---|
| Iowa | 4.75 | 32 |
| Massachusetts | 4.7 | 33 |
| Rhode Island | 4.7 | 34 |
| Indiana | 4.66 | 35 |
| New Jersey | 4.66 | 36 |
Best and Worst Months
July is the best month at 6.3 PSH. A 5 kW system produces roughly 31.5 kWh per day — nearly 2.4x what it produces in December.
December is the weakest month at 2.63 PSH. Size your system for December to ensure year-round coverage.
Is Solar Worth It in Rhode Island?
With 4.7 PSH, Rhode Island has good solar potential. The federal ITC covers 30% of installation costs through 2032.
Methodology & Data Source
NREL PVWatts v8 / NSRDB, fetched April 2026 for Providence (41.824°N, -71.4128°W). 1 kW reference system, fixed roof mount, 20° tilt, 180° azimuth, 14% losses.
Source: NREL PVWatts v8