Construction & Architecture / Solar & Energy
Solar Panel System Sizing Calculator
Energy Usage
Location & Roof Details
South: 5-6, Midwest: 4-5, North: 3-4
Account for vents, chimneys, shading
System Specifications
Accounts for inverter, wiring, shading losses
Solar Sizing Guide
How Sizing Works:
- Calculate daily energy usage from bill
- Divide by peak sun hours to get system size (kW)
- Account for system efficiency losses (15-20%)
- Determine number of panels based on wattage
Peak Sun Hours by Region:
- Southwest (AZ, NM, NV): 6-7 hours
- Southeast (FL, GA, SC): 5-6 hours
- Midwest (IL, IN, OH): 4-5 hours
- Northeast (NY, PA, MA): 3.5-4.5 hours
Cost Breakdown:
- Equipment (panels, inverters): 40-50%
- Installation labor: 15-20%
- Permits & inspections: 5-10%
- Overhead & profit: 25-30%
Tip: Federal tax credit covers 30% through 2032. Additional state/local incentives may be available.