Solar Array Sizing Calculator
Determine the solar panel wattage needed to meet your energy needs based on your location's sun hours and system efficiency.
Daily Energy Usage
Check your utility bill for average daily kWh usage
Quick reference (US averages):
Location & Sun Hours
System Efficiency
Accounts for inverter efficiency, wiring, temperature, and soiling
Results
Enter your usage and location to see results
Understanding Array Sizing
Peak Sun Hours
Peak sun hours represent the equivalent number of hours at 1,000 W/m² solar irradiance. This varies significantly by location and season.
System Losses
Real-world systems lose 15-25% of rated output due to inverter efficiency, wiring, temperature derating, soiling, and shading.
Oversizing
Many installers oversize by 10-20% to account for panel degradation and ensure production meets expectations year-round.
Net Metering
If your utility offers net metering, consider sizing to 100-110% of annual usage to maximize bill credits during sunny months.
Need a detailed site assessment?
Our team can help with shading analysis and optimized system design.