Solar Calculator
Estimate solar installation cost, annual savings, CO2 reduction, payback period, and IRR.
You will need a recent utility bill for this tool.
Solar Inputs
Enter your annual consumption from your utility bill in kWh.
Enter the solar zone you live in from the solar zone map.
Enter the approximate direction your roof faces.
Enter the electrical rate in $/kWh from your bill or utility website.
Enter any state or local incentive for solar installation.
Enter any state or local annual rebates for solar.
Choose the eGRID subregion for your electricity source, or use Natural Gas or Coal.
Use the eGRID Subregions Map in the
Carbon Footprint Calculator
to find your subregion.
Choose the interest or discount rate you would like to use.
Choose the inflation rate for electricity prices you would like to use.
Default values match the spreadsheet example: 12,000 kWh/year, Zone 3, East/West roof, $0.19/kWh.
Solar Zone Map
Use the NREL kWh/m²/day bands on the map to choose the closest calculator zone below.
Zone 1 — 3.9
Zone 2 — 4.15
Zone 3 — 4.4
Zone 4 — 4.65
Zone 5 — 4.9
Zone 6 — 5.15
Zone 7 — 5.4
Zone 8 — 5.65
Zone 9 — 5.9
Map source: NREL / National Solar Radiation Database, U.S. Annual Solar GHI.
Adjust inputs to update the model, then export the report.
Installation Cost
$0
Annual CO2 Saved
0
Payback Period
N/A
IRR%
N/A
Solar Results
| Approximate # of Panels | 0 |
|---|---|
| Annual Electricity Savings | $0 |
| CO2 Reduction / Investment | 0 |
25-Year Cash Flow
| Year | Cash Flow | Undiscounted Balance | PV of Cash Flow | Discounted Balance |
|---|