Oregon Solar Production & Irradiance Data
3.72 peak sun hours/day · 6,528 kWh/year from a 6kW system · below national average
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Oregon receives an average of 3.72 peak sun hours per day, which translates to a Global Horizontal Irradiance (GHI) of 3.72 kWh/m²/day. When solar panels are tilted at the optimal angle for Oregon's latitude, irradiance increases to 4.3 kWh/m²/day — a 16% boost over flat-mounted panels.
This puts Oregon below the national average of 4.29 peak sun hours per day. While Oregon receives less sunlight than sun-belt states, solar is still a sound investment — especially when electricity rates and local incentives are factored in. Germany, with similar sun hours, is one of the world's largest solar markets. These figures are derived from NREL solar resource maps and PVWatts reference calculations.
Expected Annual Output by System Size
| System Size | Annual Output | Avg Monthly | Annual Savings | 25-Year Savings |
|---|---|---|---|---|
| 4 kW (12-16 panels) | 4,352 kWh | 363 kWh | $669/yr | $16,725 |
| 6 kW (18-24 panels) | 6,528 kWh | 544 kWh | $1,003/yr | $25,075 |
| 8 kW (24-32 panels) | 8,704 kWh | 725 kWh | $1,338/yr | $33,450 |
| 10 kW (30-40 panels) | 10,880 kWh | 907 kWh | $1,672/yr | $41,800 |
Based on 4.3 kWh/m²/day tilt irradiance, 14% system losses, and 15.37¢/kWh electricity rate. Actual output varies by installation specifics.
Month-by-Month Solar Production in Oregon
Estimated monthly output for a 6kW system:
Solar production in Oregon peaks in July when a 6kW system generates approximately 849 kWh — about 13% of annual production in a single month. The lowest production month is December at approximately 228 kWh (3.5% of annual output). This 3.7:1 seasonal ratio is significant — battery storage or time-of-use rate plans can help smooth out this variation.
How Oregon Compares Nationally
Tips for Maximizing Solar Production in Oregon
While Oregon's 3.72 peak sun hours is below the national average, solar is still viable and cost-effective. Maximizing panel tilt angle and ensuring zero shading are critical to getting the most from your system.
Cloud cover is common in Oregon, but modern solar panels still produce 10-25% of their rated output on overcast days. Monocrystalline panels with higher efficiency ratings (20%+) perform better in diffuse light conditions and are a smart choice for Oregon homeowners.
Consider adding battery storage to your Oregon solar system. A 10-13 kWh home battery lets you store excess daytime production for evening use, maximizing your self-consumption and reducing grid dependence. This is especially valuable for backup power during outages.
Solar Irradiance Technical Data
Global Horizontal Irradiance (GHI): 3.72 kWh/m²/day. GHI measures the total solar radiation received on a horizontal surface, including direct sunlight and diffuse radiation from clouds and atmospheric scattering. This is the baseline measurement for solar resource assessment.
Tilt Irradiance: 4.3 kWh/m²/day. When panels are tilted at the optimal angle for Oregon's latitude, they receive 16% more solar radiation than flat-mounted panels. This tilt optimization is one of the easiest ways to boost your system's output.
System Output Estimation: The annual production figures use the NREL PVWatts methodology: Tilt Irradiance × 365 days × System Size × (1 − System Losses) × Inverter Efficiency. We use 14% system losses (wiring, soiling, degradation, mismatch) and 96% inverter efficiency, matching PVWatts defaults.
Oregon Solar Production FAQ
How many peak sun hours does Oregon get?▼
Oregon averages 3.72 peak sun hours per day, which is below the national average of 4.29 hours. Peak sun hours represent hours of full-intensity sunlight equivalent — a key factor in estimating solar panel output. This data is derived from NREL solar resource maps and PVWatts reference calculations.
How much electricity will a 6kW solar system produce in Oregon?▼
A 6kW solar system in Oregon produces approximately 6,528 kWh per year, or about 544 kWh per month on average. Production peaks in July (approximately 849 kWh) and is lowest in December (approximately 228 kWh). At Oregon's average rate of 15.37¢/kWh, this saves you about $1,003/year.
What is the best month for solar production in Oregon?▼
July is typically the best month for solar production in Oregon, with a 6kW system producing approximately 849 kWh. The long daylight hours and high sun angle combine for maximum energy generation. The worst month is December, producing about 228 kWh — roughly 27% of the best month's output.
How does Oregon's solar potential compare to other states?▼
Oregon's average of 3.72 peak sun hours per day puts it below the national average of 4.29 hours. A 6kW system in Oregon produces 6,528 kWh/year, compared to the national average of 7,562 kWh/year — that's -1,034 kWh/year (-14%). Even at Oregon's 15.37¢/kWh rate, solar delivers solid returns.
What affects solar panel output in Oregon?▼
Key factors affecting solar output in Oregon include: roof orientation (south-facing is ideal), tilt angle (latitude tilt of 36° is optimal), shading from trees or buildings, panel efficiency rating, and local weather patterns. Oregon's GHI (Global Horizontal Irradiance) is 3.72 kWh/m²/day, but panels tilted at the optimal angle receive 4.3 kWh/m²/day — a 16% improvement over flat-mounted panels.
More Oregon Solar Resources
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Oregon Solar Data
- ☀️ Peak Sun Hours: 3.72 hrs/day
- 📊 GHI: 3.72 kWh/m²/day
- 📐 Tilt Irradiance: 4.3 kWh/m²/day
- ⚡ 6kW Output: 6,528 kWh/yr
- 📈 Best Month: July
- 📉 Worst Month: December
- 💡 Electricity Rate: 15.37¢/kWh
- 💰 Annual Savings (6kW): $1,003
- 📋 Data: NREL Reference Data