basic

Solar Roof Savings Calculator

Annual generation and savings from rooftop PV.

Estimate the annual generation (kWh) and electricity-bill savings from a rooftop solar PV system, given system size, peak sun hours per day, system efficiency, and your retail electricity rate.

Marcus Laurent By Marcus Laurent
Reviewed by Dr. Helena Ortiz
Published Last reviewed 1 min read

Inputs

kW
%
$ /kWh

Results

Enter values and click Calculate to see results.
Was this helpful?

How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

kWh/year = system_kw · sun_hours_per_day · 365 · efficiency. Savings = kWh · electricity_rate.

In depth

Estimate the annual generation (kWh) and electricity-bill savings from a rooftop solar PV system, given system size, peak sun hours per day, system efficiency, and your retail electricity rate.