Peak Sun Hours Calculator
Convert climate band or daily insolation into planning peak sun hours (PSH) for array and production screens.
Quick answer
PSH ≈ Daily insolation (kWh/m²/day) at STC reference, or use climate-band defaults. Example: 5.0 kWh/m²/day → 5.0 peak sun hours. Use in panel sizing. Hub: Solar calculator.
Quick Peak Sun Hours Calculator
Pick a climate band (defaults shown).
Planning default for good-sun commercial sites.
Advanced Peak Sun Hours Calculator
Peak Sun Hours Results
Engineering disclaimer
Climate-band defaults are planning aids—not zip-code weather maps. Confirm with site irradiance data or PVWatts/OEM tools before procurement.
Climate band reference
| Band | Typical PSH |
|---|
People also ask
- What are peak sun hours? Equivalent full-sun hours at 1,000 W/m².
- Same as daylight hours? No—daylight is longer than PSH.
- How to use PSH? Feed into panel sizing and production tools.
Planning guidance
- Sizing: Use PSH in panel sizing.
- Yield: Reuse in production.
- Hub: Solar calculator.
Typical scenarios
- Northern industrial roof: Often 3.5–4.5 PSH planning band.
- Sunbelt commercial: 5.0–6.0 PSH common for screens.
- Shaded site: Apply derate before locking array kW.
Formula (quick reference)
PSH ≈ Insolation (kWh/m²/day) × site derate (or use climate-band default).
From solar irradiance: Insolation (kWh/m²/day) ≈ (avg W/m² ÷ 1000) × daylight hours. At STC reference, 1 kWh/m²/day ≈ 1 peak sun hour before derate. Walkthrough: how to use solar irradiance data.
Frequently Asked Questions
What are peak sun hours?
Peak sun hours are the equivalent number of hours at 1,000 W/m² that deliver the same daily energy as the actual irradiance profile.
How do I convert solar irradiance (W/m²) to peak sun hours?
Estimate daily insolation as (average W/m² ÷ 1000) × daylight hours, then apply site derate. Example: 417 W/m² over 12 h → 5.0 kWh/m²/day → ~5.0 PSH before derate. This page absorbs the “solar irradiance calculator” planning intent—not a weather-year map.
How is this different from daylight hours?
Daylight can be 10–14 hours while PSH is often 3–6 hours depending on location and season.
Is this a zip-code map?
No—this is a planning calculator with climate bands and insolation input. Use measured or mapped site data for final design.
How do I use the result?
Enter PSH into solar panel sizing and PV energy production calculators.
What about seasonal variation?
Use worst-month PSH for conservative autonomy and array screens when winters matter.
How it works
For planning, daily plane-of-array insolation in kWh/m²/day is numerically equal to peak sun hours before site derate. Climate bands provide quick defaults when insolation is unknown.
Optional average irradiance (W/m²) with daylight hours converts to insolation so “solar irradiance” queries land on the same PSH workflow.