klepZ ArrayCare

Solar by state / Alabama

Solar potential
in Alabama.

Daily irradiance4.6kWh/m² average, 4.4–4.9 across the state
Per kW installed1,269kWh a year, south-facing at 0.80 PR
Strongest monthJune6.3 kWh/m² a day
National rank13 / 51by sampled irradiance

Alabama averages 4.6 kWh per square metre a day across the 8 grid cells sampled inside it — 13th of 51 states by that measure. June is the strongest month at 6.3, December the weakest at 2.5.

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 1,269 kWh a year for every kW installed, or 8,883 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

The spread inside Alabama runs from 4.4 kWh/m²/day around Franklin County to 4.9 around Baldwin County — 10% between the dimmest and sunniest sampled cells, or about 129 kWh a year per kW installed. That is a real difference, though a roof's orientation and shading will usually move the number further than its county does.

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 8 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

June runs 2.6× stronger than December. A winter month delivers under half of a summer month, which is the normal shape for most of the country.

MonthkWh/m² a daykWh per kW installed
January 2.8 65
February 3.4 71
March 4.5 105
April 5.7 129
May 6.3 146
June 6.3 142
July 6.1 142
August 5.6 130
September 5.0 113
October 4.1 96
November 3.2 72
December 2.5 57

Monthly means across the 8 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
Baldwin County4.91,347
Coffee County4.81,305
Barbour County4.81,305
Elmore County4.61,266
Coosa County4.61,266
St. Clair County4.51,232
Franklin County4.41,218
Lauderdale County4.41,218

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 →