How long do solar panels last?

Decades, but not at full strength. Here's the lifespan, how fast output fades, and what that means in kWh.

Hank, the illustrated Solar Hank character, thinking

Solar panels last about 25 to 35 years: the US Department of Energy says the average operational lifespan rose from around 20 years in 2007 to 25–35 years in 2025 (DOE). They don't stop at that age; they fade. NREL's review of nearly 2,000 measured degradation rates found a median loss of 0.5% of output a year (Jordan and Kurtz, NREL). At that rate a panel still makes about 89% of its first-year output in year 25.

What a 7 kW system makes as it ages

kWh a year, starting from NREL PVWatts production for each city and losing 0.5% a year:

City	Year 1	Year 10	Year 20	Year 25	Year 30
Phoenix, AZ	12,285	11,743	11,169	10,893	10,623
Tucson, AZ	12,516	11,964	11,379	11,097	10,823
San Antonio, TX	10,521	10,057	9,565	9,328	9,098
Austin, TX	10,381	9,923	9,438	9,204	8,977
San Diego, CA	12,012	11,482	10,921	10,650	10,387
Fresno, CA	11,578	11,067	10,526	10,266	10,012
Chandler, AZ	12,271	11,730	11,156	10,880	10,611
Scottsdale, AZ	12,215	11,676	11,105	10,830	10,562
Gilbert, AZ	12,250	11,710	11,137	10,862	10,593
Glendale, AZ	12,278	11,736	11,163	10,886	10,617
Tempe, AZ	12,264	11,723	11,150	10,874	10,605
Peoria, AZ	12,397	11,850	11,271	10,992	10,720
Surprise, AZ	12,495	11,944	11,360	11,079	10,805
San Jose, CA	11,368	10,867	10,335	10,079	9,830
Bakersfield, CA	11,788	11,268	10,717	10,452	10,193
Clovis, CA	11,613	11,101	10,558	10,297	10,042
Chula Vista, CA	12,096	11,562	10,997	10,725	10,460
Oceanside, CA	11,886	11,362	10,806	10,539	10,278
Carlsbad, CA	11,683	11,168	10,622	10,359	10,102
Toms River, NJ	9,632	9,207	8,757	8,540	8,329
New York, NY	9,471	9,053	8,611	8,397	8,190
Elizabeth, NJ	9,317	8,906	8,471	8,261	8,056
Yonkers, NY	9,226	8,819	8,388	8,180	7,978

0.5% a year is a median across many systems, not a promise for yours. The same review notes higher rates in some climates and products. Year 30 at this rate: about 86% of year 1.

What this means for payback

Savings shrink slowly with output, about half a percent a year. In the cities I cover, a 7 kW system bought with cash pays back in 7 to 13 years, so panels keep working for years after payback (is solar worth it).

What to check in a quote

Performance warranty. It states the output the maker guarantees after a set number of years. Compare that figure with the 0.5%-a-year median above.
Product and workmanship warranties. They are separate documents with separate terms; ask for each in writing, and ask who honors them if the installer closes.
Inverter. It has its own warranty term. Ask how long it is and what a replacement costs.
Roof age. Removing and reinstalling panels for a new roof is a paid job. If the roof is near the end of its life, price the roof first.

More checks: how to check a solar quote.

What happens to panels after 25 years

They can keep running at lower output, be replaced, or be retired. Recycling processes exist for silicon and cadmium telluride panels, but in the US recycling still generally costs more than landfill disposal, DOE says (DOE). If you lease, the contract says who removes the system at the end: lease vs buy.

Run your own numbers

Enter your ZIP and bill to see first-year production and payback for your home.

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Keep reading

Is solar worth it in 2026? — Payback without the federal credit in the cities I cover, and when solar is a weak deal.
How much solar panels save — Yearly and monthly savings by utility, and why they change from month to month.
Disadvantages of solar panels — Nine downsides to weigh before you sign, with numbers from real tariffs.

Updated 2026-09-21.