Solar payback calculator widget

Your home

All amounts in US dollars.

Your home

Nearest city

Sets how much electricity each kW of panels makes in a year at your location.

Electricity use

kWh per month

Check your utility bill: most show monthly kWh. Average your last 12 months if you can.

Electricity price

cents per kWh

Starts at the US residential average. Your bill shows your own rate.

Solar system

System size

Leave blank to size the panels to cover your yearly use, or enter the size on your quote.

Installed price

Price per wattTotal quoted price

Price per watt

$per W

Enter the price from your installer quote to see cost, payback and return. Your quote divided by the system size in watts (for example, a 6 kW system is 6,000 W).

Assumptions you can change

Panel output loss

% per year

Starts at 0.5%, the median of nearly 2,000 reported rates in an NREL review.

Electricity price change

% per year

A scenario, not a forecast. Try 0% and 5% to see how much it matters.

Used directly at home

Share of the panels’ output your home uses as it is made. 100% assumes all of it offsets power you would otherwise buy, up to your annual use.

Add a home battery

A battery only adds savings when you use less than 100% of your solar power directly. Lower “Used directly at home” under assumptions to model that.

Results

Payback period

Add your installer’s quoted price to see payback

First-year savings: $1,962
Savings over 25 years: $66,899
System size: 7.1 kW; Sized to cover your yearly use
First-year generation: 10,788 kWh

Cumulative savings over 25 yearsAdd your quoted price to compare against the cost.

Year-by-year table

Generation and savings for each of the 25 years
Year	Generation (kWh)	Price per kWh	Saved that year	Saved so far
1	10,788	$0.182	$1,962	$1,962
2	10,734	$0.187	$2,011	$3,973
3	10,680	$0.193	$2,061	$6,035
4	10,627	$0.199	$2,112	$8,147
5	10,574	$0.205	$2,165	$10,312
6	10,521	$0.211	$2,219	$12,530
7	10,468	$0.217	$2,274	$14,804
8	10,416	$0.224	$2,330	$17,134
9	10,364	$0.230	$2,388	$19,522
10	10,312	$0.237	$2,447	$21,970
11	10,261	$0.244	$2,508	$24,478
12	10,209	$0.252	$2,571	$27,049
13	10,158	$0.259	$2,634	$29,683
14	10,107	$0.267	$2,700	$32,383
15	10,057	$0.275	$2,767	$35,150
16	10,007	$0.283	$2,836	$37,986
17	9,957	$0.292	$2,906	$40,892
18	9,907	$0.301	$2,979	$43,871
19	9,857	$0.310	$3,053	$46,923
20	9,808	$0.319	$3,128	$50,052
21	9,759	$0.329	$3,206	$53,258
22	9,710	$0.338	$3,286	$56,544
23	9,662	$0.349	$3,367	$59,911
24	9,613	$0.359	$3,451	$63,362
25	9,565	$0.370	$3,537	$66,899

Savings count only electricity your home no longer buys. Power sent to the grid is valued at zero. Grid emissions data has not been verified yet, so no carbon figure is shown. See the methodology for every formula and source.