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RoofPayback
Updated Oct 15

Solar panels in Madison, WI: payback and output

A kW of south-facing panels in Madison produces about 1,333 kWh a year, about the same as Milwaukee, the Wisconsin reference city. Summer months produce 2.0× what winter does. To cover a typical 10,500 kWh/yr home on paper you'd need roughly 7.9 kW.

Output by month in Madison (kWh per kW)

Best: Jul · weakest: Dec.

Jan: 75 kWhJanFeb: 81 kWhFebMar: 123 kWhMarApr: 122 kWhAprMay: 141 kWhMayJun: 146 kWhJunJul: 152 kWhJulAug: 137 kWhAugSep: 121 kWhSepOct: 96 kWhOctNov: 73 kWhNovDec: 67 kWhDec

Example 7 kW system in Madison

Installed cost (example)
$21,000
Production, year 1
9,334 kWh
Savings, year 1
$1,779
Payback
11.2 years
25-year net gain
$33,392

Uses the Wisconsin average price (19.06¢/kWh, EIA July 2026), full net metering and no incentives. Your utility's rate and export credit may differ — change them below.

Roof direction in Madison

Yearly output per kW of panels at a 20° pitch, and how it compares with a south-facing roof.

Roof faceskWh per kW/yrvs. south
South1,333—
Southeast1,272−5%
Southwest1,275−4%
East1,121−16%
West1,126−16%
East-west (split)1,124−16%

Calculate your home in Madison

1 · Your roof
Roof faces
Pitch

About 8.0 kW would cover 100% of your yearly use.

2 · Your usage
3 · Prices
Paying with
Advanced assumptions

Estimated payback

11.2 years

A solid case if you plan to stay in the home.

≈ $148/month off your bill in year 1

025y
Year-1 savings
$1,779
25-yr net gain
$33,392
Return (IRR)
8.2%
Net cost
$21,000

Cumulative savings minus cost

-$21k$0$33kYear 0510152025Break-even · 11.2 yrs

Production vs. use by month

9,334 kWh/yr

Jan: 525 kWhJanFeb: 568 kWhFebMar: 858 kWhMarApr: 855 kWhAprMay: 988 kWhMayJun: 1,023 kWhJunJul: 1,065 kWhJulAug: 956 kWhAugSep: 848 kWhSepOct: 676 kWhOctNov: 508 kWhNovDec: 466 kWhDec
Production Your use

Covers 40% of your use directly; 45% of the output is used on the spot.

Which size pays off best?

Same usage and prices, only size changes. Best 25-year gain: 8 kW.

SizeCostYear-1 savingsPayback25-yr gain
3 kW$9,000$76212.0 years$12,882
4 kW$12,000$1,01711.6 years$18,010
5 kW$15,000$1,27111.4 years$23,137
6 kW$18,000$1,52511.3 years$28,264
7 kW$21,000$1,77911.2 years$33,392
8 kW$24,000$2,00111.2 years$38,451
10 kW$30,000$2,00113.4 years$35,860
12 kW$36,000$2,00115.6 years$29,860
Estimate based on NLR PVWatts and EIA data. How we calculate.

Read the full Wisconsin solar guide for net metering, orientation and price trends.

Other cities in Wisconsin

Cities with similar sunshine

Solar in Madison: common questions

Are solar panels worth it in Madison, WI?

For an example 7 kW system costing $21,000 on a home using 10,500 kWh a year, payback in Madison is 11.2 years with full net metering and 15.0 years if exports earn half the retail rate, at the Wisconsin average price of 19.06¢/kWh (EIA, July 2026).

How much electricity do solar panels produce in Madison?

About 1,333 kWh per year for each kW of south-facing panels at a 20° pitch (NLR PVWatts, typical-year weather), from 67 kWh in Dec to 152 kWh in Jul.

What size solar system does a home in Madison need?

About 7.9 kW to cover 10,500 kWh a year. Divide your own annual use by 1,333 kWh per kW for a first estimate; if exports earn less than retail, a smaller system often pays back faster.

Does roof direction matter in Madison?

Yes. Per kW at a 20° pitch: south 1,333 kWh, southeast 1,272 kWh, southwest 1,275 kWh, east 1,121 kWh, west 1,126 kWh, east-west (split) 1,124 kWh a year. South-facing roofs produce the most; east or west roofs still work, with less output.

Guides for going solar in Madison

Data: NLR PVWatts v8 (U.S. DOE National Laboratory of the Rockies, formerly NREL), TMY weather near Madison (43.07, -89.4), 14% losses, retrieved 2026-10-11. Published 2026-10-15.