Solar Panel Output Calculator

Total DC capacity (e.g., 10 × 400W = 4000W).

Average daily full-sun equivalent.

Inverter, wiring, dirt, temp losses (typical 75–90%).

Days of operation per month.

Solar Panel Output & Energy Production

The Solar Panel Output Calculator estimates real-world kWh production based on panel size, location, and system losses.

Formula

Daily kWh = (Panel Watts × Sun Hours × Efficiency) / 1000

Average Peak Sun Hours (USA)

LocationSun Hours
Phoenix, AZ6.5
Los Angeles, CA5.6
Denver, CO5.3
New York, NY4.2
Seattle, WA3.6

Typical System Efficiency

  • Inverter: 95–98%
  • Wiring: 98%
  • Temperature: 85–95%
  • Dirt/Shading: 95%
  • Total: 75–90%

Examples

  • 5 kW system, 5 sun hours, 85% efficiency → 21.25 kWh/day
  • 10 kW, 4.5 sun hours, 80% → 36 kWh/day

Monthly & Annual Output

Multiply daily kWh by days/month and 365 for yearly.

Sizing Tips

  • Use NREL PVWatts for precise modeling
  • Account for panel degradation (0.5%/year)
  • Optimize tilt = latitude
  • Avoid shading 9 AM–3 PM

ROI & Savings

Pair with Energy Cost to estimate bill savings.

Conclusion

Accurate output prediction ensures proper system sizing. Use with Battery Capacity and Inverter Sizing.