Solar Panel Calculator

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Solar PPA vs Buy Calculator

Compare paying cash, taking a loan and signing a lease or PPA over 25 years.

kW DC
From your quote, or your state's average.
$/W
Average residential price. Your bill shows yours.
¢/kWh
From NREL PVWatts for your state.
kWh/kW
Third-party option
From your PPA quote.
¢/kWh
From your lease quote.
$/month
Written into the contract.
%
%
More settings
$
$
% a year
% a year

Your result

Enter your numbers and press the button. Your result appears here.

A PPA charges you for each kWh the panels make, usually with a yearly escalator. Compare the 25-year total with buying the system.

How it works

Cash: savings − net cost. Loan: savings − down payment − all loan payments. PPA: savings − kWh × rate. Lease: savings − monthly payments. Rates rise by the escalator each year.

Example: over 25 years an 8 kW system nets $26,059 bought for cash, $8,156 with a loan and −$8,350 on a PPA.

Common questions

Is it better to buy or lease solar?

Buying usually saves the most over 25 years if you can pay cash or get a fair loan. Leases and PPAs need no money up front but save less, and the installer keeps the panels.

What is a PPA escalator?

A clause that raises the price per kWh each year, often by 1% to 3%. Over 25 years it adds a lot to what you pay.

Is there still a federal solar tax credit?

Not for homeowners who buy their system. The 30% Residential Clean Energy Credit ended for systems installed after December 31, 2025. Leased systems and PPAs can still carry a business credit (48E) that the installer claims.

Related calculators

Sources

  • EnergySage, Solar panel cost by state (updated November 6, 2026): https://www.energysage.com/local-data/solar-panel-cost/
  • U.S. EIA, Electric Power Monthly, Table 5.6.B (residential price, Jan–Aug 2026): https://www.eia.gov/electricity/monthly/epm_table_grapher.php?t=epmt_5_6_b
  • NREL PVWatts v8 (20° tilt, south-facing, 14% losses), state results compiled by TheGreenWatt: https://thegreenwatt.com/average-peak-sun-hours-by-state/
  • NREL, Jordan and Kurtz, Photovoltaic Degradation Rates: An Analytical Review: https://docs.nrel.gov/docs/fy12osti/51664.pdf