Solar Panel ROI & Energy Savings Calculator

Calculate solar system payback period, annual electricity savings, federal tax credits, and lifetime ROI.

Configurable Calculation Inputs

Solar Array Size (kW): slider (Default: 8 kW)
Average Cost per Watt ($): number (Default: 2.8 $/W)
Current Monthly Electric Bill: number (Default: 180 $)
Average Peak Sun Hours / Day: slider (Default: 4.5 hrs)
Federal / Local Tax Credit (%): number (Default: 30 %)

Mathematical Formula: Solar System Net Payback Equation

          Payback Years = (Gross System Cost - Tax Credits - Rebates) / Annual Electric Bill Savings
        

Calculates the breakeven timeline and 25-year cumulative energy savings taking into account utility price inflation.

Comprehensive Guide & Context

Understanding Net Energy Metering

Net metering allows solar homeowners to sell surplus daytime electricity back to the grid, crediting their utility accounts for nighttime consumption.

Worked Calculation Examples

Residential 8kW System in Sunny Region

8kW solar array at $2.80/W, $180/mo electric bill, 30% federal credit.

Result: 6.9 Years Payback · $38,500 25-Year Net Profit

Frequently Asked Questions

What is the federal solar investment tax credit (ITC)?

The federal Residential Clean Energy Credit allows taxpayers to deduct 30% of the cost of installing solar energy systems from their federal taxes.