klepZ ArrayCare

Solar by state / Rhode Island

Solar potential
in Rhode Island.

Daily irradiance4.0kWh/m² average, 4.0–4.0 across the state
Per kW installed1,096kWh a year, south-facing at 0.80 PR
Strongest monthJuly6.2 kWh/m² a day
National rank35 / 51by sampled irradiance

Rhode Island averages 4.0 kWh per square metre a day across the 3 grid cells sampled inside it — 35th of 51 states by that measure. July is the strongest month at 6.2, December the weakest at 1.6.

What that means for an array

On the same assumptions the ArrayCare check uses — a south-facing array and a 0.80 performance ratio — that works out to roughly 1,096 kWh a year for every kW installed, or 7,672 kWh for a 7 kW system. Irradiance is what arrives; production is what a specific array, at a specific tilt, with specific shading and losses, converts. Those are different numbers and a real quote will use the second.

Where in the state

Every sampled cell in Rhode Island returned the same annual figure, which is what a state small enough to sit inside one or two grid cells looks like at this resolution.

How precise this is

These figures come from NASA POWER's solar climatology, a grid of roughly 55 km cells. Two points 40 km apart return the same numbers, which is why this page covers a state and prints the range across 3 sampled cells rather than claiming a figure for a town or a ZIP code. Local terrain, coastal fog and elevation all move the real number at a given address, and none of them are visible at this scale.

Through the year

July runs 4× stronger than December. That is a steep seasonal swing: a winter month delivers well under half what a summer one does, and an array sized around the annual figure will run far below it for months at a time.

MonthkWh/m² a daykWh per kW installed
January 1.9 43
February 2.7 58
March 3.8 89
April 5.0 113
May 5.6 130
June 6.1 137
July 6.2 144
August 5.5 129
September 4.5 101
October 3.0 70
November 2.1 46
December 1.6 36

Monthly means across the 3 sampled cells. The per-kW column applies a south-facing orientation and a 0.80 performance ratio to the irradiance beside it — the same arithmetic the array check uses.

The cells behind these numbers

Each row is one NASA POWER grid cell, named for the county its sample point falls in. Two counties in the same cell would return the same numbers, so only one of each appears.

Sample pointkWh/m² a daykWh a year per kW
Kent County4.01,096
Bristol County4.01,096
Providence County4.01,096

Against the rest of the country

For scale, Arizona leads the country at 5.8 kWh/m²/day and Alaska trails at 2.5. The national spread is narrower than most people expect — the sunniest state is not ten times the dimmest, it is about 2.3×.

Sunlight is only one input into whether solar pays somewhere. Electricity prices, net-metering rules, incentives, roof condition and shading routinely matter more than the difference between two neighbouring states, and none of them are on this page. ArrayCare is independent, sells nothing, and is not a quote.

States with similar sun

All 51 states ranked →