Solar in Cloudy States: The Data That Surprises Everyone

If you live in the Pacific Northwest, the Midwest, or New England, you have probably heard this at least once: "Solar doesn't make sense where you live." It is one of the most persistent myths in residential energy, and it is flatly contradicted by the data. Some of the best solar markets in the country get far less sunshine than Phoenix or Las Vegas — and homeowners there are still saving thousands of dollars a year.

Let's look at what the numbers actually say.

How Much Sun Do You Really Need?

Solar panels do not need blazing direct sunlight to generate electricity. They need light — and even on an overcast day, diffuse sunlight still reaches your roof. Modern monocrystalline panels convert roughly 20–22% of incoming light into electricity, and their performance in cloudy conditions has improved dramatically over the past five years thanks to advances in cell architecture like passivated emitter rear contact (PERC) and heterojunction (HJT) technology [1].

The metric that matters is peak sun hours (PSH) — the number of hours per day that solar irradiance averages 1,000 watts per square meter. Phoenix gets about 6.5 PSH annually. Seattle gets about 3.7. But here is the thing: 3.7 peak sun hours is still enough to power a well-sized residential system and deliver a strong return on investment.

The Leaderboard You Didn't Expect

According to NREL's PVWatts calculator and SEIA installation data, these states rank among the top 15 for residential solar installations per capita — despite being far from the sunniest [2][3]:

Massachusetts averages just 4.2 PSH per day, yet it ranks 4th nationally in solar capacity per capita. The SMART incentive program, net metering, and high electricity rates ($0.29/kWh average in 2025) mean a typical 8 kW system pays for itself in under 6 years.

New Jersey gets about 4.4 PSH per day and ranks 6th nationally. The state's SREC-II program pays homeowners for every megawatt-hour their panels produce, adding $40–$60 per SREC on top of regular utility savings.

Connecticut averages 4.0 PSH and has one of the fastest-growing residential solar markets in the country. The Residential Solar Investment Program combined with net metering and electricity rates above $0.27/kWh drive strong economics.

Oregon gets just 3.9 PSH on average, but Portland has seen a 34% increase in residential installations since 2023 [4]. The Oregon Solar + Storage Rebate Program offers up to $5,000 for solar and $2,500 for battery storage.

Minnesota might surprise you the most. At 4.1 PSH, it is solidly in the middle of the pack for sunshine, but its Solar*Rewards program and community solar garden legislation have made it a quiet leader in distributed solar.

Why Cloudy States Often Have Better Solar Economics

Here is the counterintuitive part: solar economics are not primarily driven by how much sun you get. They are driven by the gap between your electricity cost and your solar cost. And that gap tends to be largest in states with expensive electricity — which are disproportionately in the cloudy Northeast and Pacific Northwest.

Consider the math. In Arizona, residential electricity averages about $0.13/kWh. A 7 kW system there produces roughly 11,500 kWh per year, saving about $1,495 annually. In Massachusetts, that same 7 kW system produces about 8,800 kWh per year — 23% less energy — but at $0.29/kWh, the savings come to $2,552 per year. That is 70% more annual savings despite less sunshine [5].

When you factor in state incentives, the picture gets even more lopsided. Massachusetts homeowners can stack the 30% federal ITC (now under Section 48E for leased and PPA systems), the SMART program payments, and the state's personal income tax credit of 15% up to $1,000. A system that costs $24,500 before incentives might net out to $14,000–$16,000 after all credits and rebates, with a payback period under 6 years [6].

Temperature Actually Helps Cooler Climates

There is another factor working in favor of cloudy states that rarely gets mentioned: temperature coefficients. Solar panels lose efficiency as they heat up. Most panels lose about 0.3–0.4% of their rated output for every degree Celsius above 25°C (77°F). On a 100°F day in Phoenix, panel surface temperatures can reach 150°F or higher, reducing output by 10–15%.

In Portland or Boston, summer highs of 80–85°F mean panels operate much closer to their rated efficiency. This partially offsets the lower irradiance. NREL data shows that the actual performance ratio — real-world output versus theoretical maximum — is often higher in cooler climates than in desert states [7].

What the Payback Periods Actually Look Like

Here is a comparison of estimated payback periods for a typical 8 kW residential system in 2026, accounting for local electricity rates, incentives, and solar production:

Arizona comes in at about 8.5 years. Not bad, but not the fastest. California lands around 6.5 years thanks to high rates and NEM 3.0 battery incentives. Massachusetts hits roughly 5.5 years with SMART stacking. New Jersey is about 6 years with SREC-II income. Connecticut runs around 6.5 years. Oregon comes in at approximately 7 years with the state rebate. And Minnesota is around 8 years with Solar*Rewards [5][6].

The sunny states are not dramatically better — and in several cases, the cloudy states win outright.

Snow, Clouds, and Other Practical Concerns

What about snow? It is a fair question. Snow cover does reduce production, typically by 2–5% annually in northern states. But panels are installed at an angle, and snow tends to slide off relatively quickly. Dark panels also absorb heat and accelerate melting. Most solar installers in northern climates account for snow losses in their production estimates, and the economics still work [8].

Prolonged overcast days do reduce daily output, but net metering smooths this out over the year. Your panels overproduce in the long summer days (even cloudy northern states get 15+ hours of daylight in June) and you draw credits in winter. The annual math is what matters, not any single gray Tuesday in February.

The Bottom Line

If you have been told solar does not make sense in your state because of clouds, rain, or snow, the data says otherwise. The states with the fastest solar payback periods are not the sunniest — they are the ones with high electricity rates, strong incentive programs, and favorable net metering policies. Geography matters less than economics.

Want to see what solar and battery savings look like for your specific location? Plug your zip code into the EnergyScout solar calculator to get a personalized estimate based on your local irradiance, utility rates, and available incentives. You can also explore state and local incentives and compare solar-only vs. solar-plus-battery economics using our system toggle tool.

The sun is shining on cloudy states — and the savings are real.

Sources

1. National Renewable Energy Laboratory (NREL). "Best Research-Cell Efficiency Chart." https://www.nrel.gov/pv/cell-efficiency.html
2. NREL PVWatts Calculator. https://pvwatts.nrel.gov/
3. Solar Energy Industries Association (SEIA). "Solar State by State." https://www.seia.org/states-map
4. Oregon Department of Energy. "Solar + Storage Rebate Program." https://www.oregon.gov/energy/incentives/pages/solar-storage.aspx
5. U.S. Energy Information Administration (EIA). "Electric Power Monthly — Average Retail Price of Electricity." https://www.eia.gov/electricity/monthly/
6. Database of State Incentives for Renewables & Efficiency (DSIRE). https://www.dsireusa.org/
7. NREL. "Weather-Corrected Performance Ratio." Technical Report NREL/TP-5200-78948.
8. Northern Arizona University. "Effects of Snow on Photovoltaic Performance." https://solar.nau.edu/