Sun Hours Calculator
Solar & Renewable EnergyCalculate average daily sun hours based on your location, season, and weather conditions.
Enter your latitude, select the season, and optionally provide average cloud cover to get accurate sun hour estimates.
Calculator
Formula & Methodology
Calculates sun hours using latitude-based solar radiation models adjusted for seasonal variations and cloud cover.
This formula has been verified by certified solar engineers and complies with industry standards.
Why Accuracy Matters
Precision in solar calculations is the difference between an efficient, cost-effective system and one that underperforms or wastes money. A variance of just 10% in system sizing can lead to either significant curtailment losses or reliance on grid power during peak rates.
Our calculators utilize data models based on NREL (National Renewable Energy Laboratory) standards to provide the most reliable estimates possible. Whether you are dimensioning a battery bank for autonomy or calculating payback periods, understanding these metrics empowers you to make data-driven decisions for your energy independence.
Expert Tips & Best Practices
- Peak sun hours are different from daylight hours. They represent the equivalent hours of 1000 W/m² solar irradiance.
- Cloud cover can reduce solar output by 50-80%. Always account for local weather patterns in your calculations.
- Use historical weather data from NREL's PVWatts for more accurate regional estimates.
- Winter months typically have 30-50% fewer sun hours than summer in temperate climates.
Frequently Asked Questions
What are peak sun hours?
Peak sun hours represent the equivalent number of hours per day when solar irradiance averages 1000 watts per square meter. This is the standard used to rate solar panel output.
How does latitude affect sun hours?
Locations closer to the equator receive more consistent sun hours year-round. Higher latitudes experience greater seasonal variation, with significantly fewer sun hours in winter.
Calculator Stats
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Verified by Experts
Our calculators are developed and verified by NABCEP-certified solar professionals with 15+ years of field experience. All formulas comply with IEC 61724 and IEEE 1547 standards.