Solar Panel Output Calculator
Calculate how much electricity your solar panels will produce per day, month, and year.
Enter panel wattage, sun hours, and efficiency.
Solar Energy Output
Solar panel output depends on panel wattage, sunlight hours, and system efficiency.
Daily kWh = (Panel Wattage × Number of Panels × Peak Sun Hours × Efficiency) / 1,000
Monthly kWh = Daily kWh × 30
Yearly kWh = Daily kWh × 365
System efficiency accounts for losses from inverters, wiring, temperature, dust, and shading. Typical system efficiency is 75–85%.
Average peak sun hours by region:
- Arizona / Southern Spain: 6–7 hours
- California / Southern Europe: 5–6 hours
- Northeast US / UK: 3–4 hours
- Pacific Northwest / Northern Europe: 2.5–3.5 hours
Common panel wattages:
- Standard residential: 350–400 W
- Premium residential: 400–450 W
- Commercial: 500–600 W
Typical US home uses ~30 kWh/day (900 kWh/month)