AK · solar resource

Peak sun hours in Alaska

Alaska averages 3 peak sun hours a day across the year, 50th of the 50 states. At that figure a 400-watt panel produces about 0.92 kWh a day after real-world losses, and covering the 900 kWh average US bill takes about 33 panels. Anchorage, the state's biggest city, sits at 3 hours, close enough to the statewide figure to use either, though elevation and distance from water still move the number street by street.

cloudy-country sun: 3 of a possible ~6.5 hours

Panel counts for Alaska bills

Computed at Alaska's 3 hours with 400W panels and the 0.77 derate; the US-average column shows what the same bill takes at 4.5 hours, so you can see what your state's sun is worth in hardware.

Monthly usageAlaskaSystem sizeUS average
500 kWh/mo18 panels7.2 kW12 panels
750 kWh/mo27 panels10.8 kW18 panels
900 kWh/mo33 panels13.2 kW22 panels
1,000 kWh/mo36 panels14.4 kW24 panels
1,500 kWh/mo54 panels21.6 kW36 panels
2,000 kWh/mo72 panels28.8 kW48 panels

Your bill, Alaska sun

From your bill; how to find it. The average Alaska home ran 578 kWh a month in 2024.
System size (DC)
Roof area, with racking gaps
Expected output per month

What 3 hours means in practice

Alaska is at the cloudy end of the table: 50th of 50 at 3 peak sun hours, 33% under the national average. Covering the 900 kWh average bill takes 33 panels here against 22 nationally. Solar still works at this latitude and cloud cover, and panels run cooler here, which claws a little of it back.

How a Alaska year is shaped

The 3-hour figure is an annual average, and no month is average. These are the twelve monthly means for Alaska from NASA's 2001-2020 solar climatology, each as a share of the state's own annual mean, with that share applied to the 3-hour planning figure. June and December are marked.

MonthShare of the annual averagePeak sun hours (est.)
January 10% 0.3
February 35% 1.0
March 98% 2.9
April 165% 5.0
May 202% 6.1
June 213% 6.4
July 182% 5.5
August 141% 4.2
September 90% 2.7
October 41% 1.2
November 14% 0.4
December 6% 0.2

Summer dominates Alaska's solar year. June delivers 213% of the annual average and December 6%, a 38.8-to-one spread against Washington's 7.8 in second place, and 64% of the year's light arrives in four months. The December row above works out to roughly 0.2 hours a day. That is not a shortfall you fix by adding panels. It is why off-grid builds here run a generator through the dark months and treat the array as a May-to-August machine.

Count the months that beat the annual average and Alaska has five, April through August, holding 75% of the year's sunlight between them. March is the month that misses the cut, which is a useful thing to know if you are planning around a shoulder season.

Bills here are small, which changes the shape of the whole decision: EIA put the average Alaska household at 578 kWh a month in 2024, 33% under the national 863 and among the lowest in the country. 21 panels cover it across a year, and 375 would be needed to cover it from December sun alone, 17.9 times as many. A gap that wide is what pushes people here onto net metering rather than a battery bank.

Alaska is one of the states where a statewide number does the most damage: it has the 1st widest internal spread of the fifty. Across the 20 grid cells sampled here the southeast runs 39% sunnier than the northwest. Held against the 3-hour statewide figure that is roughly 3.6 hours at one end and 2.4 at the other, which is the difference between two quite different quotes. Nobody should size a Alaska roof off the state average without checking which end of the state it sits on.

Where these come from. The monthly shares are NASA POWER's ALLSKY_SFC_SW_DWN climatology (2001-2020), averaged over the 20 one-degree grid cells covering Alaska. POWER measures a horizontal surface, so its shape is reliable and its absolute level is not the same quantity as a tilted-array peak sun hour; the hours column is the shape applied to our statewide figure, not a second measurement of it. A fixed array tilted toward the equator flattens the curve, so a real December runs a little better than the share above suggests. Full treatment on the methodology page.

What that sun is worth on a Alaska bill

EIA, 2024 residential averagesAlaskaUnited States
Average home's monthly use578 kWh863 kWh
Price per kilowatt-hour24.82¢16.48¢
Average monthly bill$143.54$142.26
One 400W panel, a year's output337 kWh506 kWh
What that output displaces$84$83

Alaska pays 24.82¢ a kilowatt-hour, 6th highest in the country and 51% over the national 16.48¢. A single 400-watt panel therefore displaces about $84 of electricity a year here. Prices above the national line do more for a solar case than an extra half hour of sun does, because the sun sets the numerator and the rate sets what it is worth.

Which is why the sun ranking undersells Alaska. It places 50th of fifty for sunlight and 17th for what a panel actually earns, a jump of 33 places, and the second number is the one that shows up on a bill. Compare it with a state that gets similar sun: Michigan gets more sun (3.8 hours to Alaska's 3) and pays 19.3¢ against 24.82¢, so one panel is worth about $1 more a year in Alaska than in Michigan.

Two warnings on those dollar figures. They are displaced electricity and nothing else: no install cost, no incentive, no financing, and no assumption about how your utility settles a surplus, which is the single biggest unknown in the sum. And a state average hides the utility you are actually on; 24.82¢ is every Alaska residential customer averaged together, and neighbouring territories can differ by more than the gap between two states in the ranking.

Getting a number for your address

For a location-exact figure, run your address through NREL's free PVWatts; it uses measured weather for your grid cell and will also model roof tilt and direction, which statewide numbers cannot. Then compare its annual kWh against a quote's promise before you sign anything.

Questions people ask

How many solar panels do I need in Alaska?

About 33 400-watt panels (13.2 kW) for the 900 kWh a month an average US home uses, at Alaska's 3 peak sun hours. For the average Alaska home specifically, which EIA measured at 578 kWh a month in 2024, it is 21. Your own bill is the variable that matters, and the calculator takes any figure.

Is 3 peak sun hours good for solar?

It is below the 4.5-hour national average but far from disqualifying. Panel counts run about 50% higher here for the same bill, and the December trough measured above deserves respect in any off-grid plan. Grid-tied systems ride through it on net metering.

How much is one solar panel worth a year in Alaska?

About $84. One 400-watt panel at Alaska's 3 peak sun hours makes roughly 337 kWh a year after the 0.77 derate, and Alaska residential electricity averaged 24.82¢ a kilowatt-hour in 2024 (EIA), which puts Alaska 17th of the 50 states on this measure against 50th on sunlight alone. That figure is displaced electricity only. It says nothing about install cost, incentives, or how your utility settles a surplus.

Do peak sun hours change with the seasons in Alaska?

Yes, by a factor of 38.8 here. NASA's 2001-2020 climatology puts Alaska's June at 213% of the annual average and December at 6%, so the 3-hour figure on this page is the midpoint of a curve running from roughly 6.4 hours a day down to 0.2. Grid-tied homes bank the summer surplus as credit; off-grid designs have to size for the trough, and in Alaska that means 375 panels for an average local bill instead of 21.

Size a system under Alaska sun

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