How Long Do Commercial Solar Panels Last? Lifespan and Degradation
Updated 23 October 2026 · SEO Dons Editorial
How long do commercial solar panels last?
The current datasheets reviewed for this page warrant output for 30 years: Jinko, Trina, Aiko, DMEGC, Canadian Solar and LONGi each print a 30-year power warranty. Energy Saving Trust's guidance for homes says panels "should last 25 years or more". A warranty period is not a failure date. A module keeps generating after year 30 at a lower level, and the warranty fixes the lowest output its maker will stand behind.
The product warranty, which covers defects rather than output, is shorter: 12 to 15 years on these sheets. The two are different covers with different claim routes, covered on the commercial solar warranties page. For what else to check on the module itself, see the commercial PV panels page.
How fast do commercial solar panels degrade?
An NREL review of field measurements assembled "nearly 2000 degradation rates" from the literature and found a median of 0.5% a year. A later NREL study of commercial, industrial and utility-scale systems, published by the US Department of Energy on 27 June 2023, put the median performance loss at around 0.75% a year across nearly 19,000 inverters. It also found the rate "climate-dependent, with panels degrading slower in cooler climates", and that loss rates "did not differ much on account of different module technologies".
Three limits apply. Neither gives a UK figure: the review pools published studies and the fleet study covers US systems. The fleet number is whole-system performance loss, which includes more than the modules. And the review draws on 40 years of field testing, which predates today's n-type modules, while the DOE summary reports no n-type figure. IEA PVPS Task 13 (February 2025) notes that UV-induced degradation "occurs in some PV modules but is manageable by using UV-stable designs and encapsulation materials", and that degradation in polymer encapsulation "remains a major issue". Ask for test evidence for the exact bill of materials, not a technology label.
What does a 25-year output curve look like?
The table applies the warranty terms printed on the sheets to years 1 to 30, next to straight lines from the two field medians. Each warranty line is 100 minus the first-year allowance minus the annual allowance for every later year.
| Output as % of nameplate at the end of year | 1 | 5 | 10 | 15 | 20 | 25 | 30 | Average, years 1–25 |
|---|---|---|---|---|---|---|---|---|
| Warranty line: up to 2% in year 1, then 0.45% a year (Canadian Solar PERC sheet) | 98 | 96.2 | 93.95 | 91.7 | 89.45 | 87.2 | 84.95 | 92.6 |
| Warranty line: 1% then 0.40% (Trina Vertex N, Jinko 54HL4M) | 99 | 97.4 | 95.4 | 93.4 | 91.4 | 89.4 | 87.4 | 94.2 |
| Warranty line: 1% then 0.35% (Jinko, Aiko, DMEGC, LONGi, Canadian Solar TOPCon) | 99 | 97.6 | 95.85 | 94.1 | 92.35 | 90.6 | 88.85 | 94.8 |
| Warranty line: 1% then 0.30% (Canadian Solar HJT sheet) | 99 | 97.8 | 96.3 | 94.8 | 93.3 | 91.8 | 90.3 | 95.4 |
| Field median, 0.5% a year from year 0 (NREL review) | 99.5 | 97.5 | 95 | 92.5 | 90 | 87.5 | 85 | 93.5 |
| Field median, 0.75% a year from year 0 (NREL fleet study) | 99.25 | 96.25 | 92.5 | 88.75 | 85 | 81.25 | 77.5 | 90.25 |
The 1% and 0.35% line reaches 90.6% at year 25 and 88.85% at year 30, the two figures Aiko prints on its Comet 3N72 chart. Canadian Solar's PERC terms leave 84.95% at year 30. Between the 2% and 0.45% line and the 1% and 0.35% line, the 25-year average differs by 2.2 points: for example, a hypothetical array that would produce 200,000 kWh a year with no degradation would produce about 4,400 kWh a year less on the first line.
Warranty lines are ceilings on loss that a maker will allow, not forecasts, and the field medians are straight-line simplifications of older fleets. A yield model also has to say which it used. PVGIS says its recommended 14% system loss is set "considering the system losses and the losses due to ageing", so a model that adds a separate degradation curve on top of 14% should show how it avoids counting ageing twice.
What wears out first on a commercial PV system?
| Part | What the sources state |
|---|---|
| Modules | 30-year power warranties on the sheets above; Energy Saving Trust says panels "should last 25 years or more" |
| Inverter | Energy Saving Trust (homes): replace "after around 12 years"; SMA Sunny Tripower 125: standard warranty 5 years, extendable to 10, 15 and 20 |
| DC cable | Elsewedy H1Z2Z2-K solar cable: "Service life exceeding 25 years" |
| Mounting, connectors, monitoring | Their own manufacturers' terms, which are separate from the module warranty |
| Roof covering and lease | Set by the building and the property agreement, not by the array |
The inverter is the part to plan for. A cash-flow model that runs 25 years with no inverter event leaves out a likely mid-life item, whether that is a replacement or an extended warranty. The repowering page covers mid-life inverter swaps and the inverter types page covers the options.
What ends an array's life early: the roof, the lease or the building?
Often none of the modules. A 30-year module warranty on a roof covering with ten years left means the array comes off and goes back on once in its life, which is a cost and a point to check against the roof's own warranty. A roof licence or lease shorter than the payback period leaves the question of who owns the system when it ends. A sale or change of use of the building raises the same question.
So the useful comparisons are the roof's remaining life against the array's, and the property agreement's term against the payback period on the payback, ROI and IRR page. The roof guide covers roof condition, and end of life for the modules themselves is on the recycling and WEEE page. An enquiry about a specific roof and lease can be sent through this site's form. Comparing quotes for a new array? Ask each installer for the degradation terms printed on the datasheet, then request a quote; we reply by email.
Sources
- NREL (record on US Department of Energy OSTI): Photovoltaic Degradation Rates: An Analytical Review, Jordan and Kurtz, June 2012, checked 22 October 2026.
- US Department of Energy: Success Story: A Clearer Picture of U.S. Solar Power Performance, 27 June 2023, checked 22 October 2026.
- IEA PVPS Task 13: Degradation and Failure Modes in New Photovoltaic Cell and Module Technologies, February 2025, checked 22 October 2026.
- Energy Saving Trust: Solar panels: costs, savings and benefits explained, last updated 1 October 2026 (household guidance), checked 22 October 2026.
- SMA: Sunny Tripower 125 product page (used for that product only), checked 22 October 2026.
- Elsewedy Electric: H1Z2Z2-K solar cable (used for that product only), checked 22 October 2026.
- European Commission Joint Research Centre: PVGIS data sources and calculation methods, checked 22 October 2026.
- JinkoSolar: JKM650-670N-66QL6-BDV datasheet, © 2026; JKM495-520N-54HL4M-BDV datasheet, © 2025, checked 22 October 2026.
- Trina Solar: Vertex N TSM-NEG19RC.20 datasheet, TSM_EN_2025_D, checked 22 October 2026.
- Canadian Solar: CS6.3-66TB datasheet v1.11; CS7N-MB-AG datasheet v2.8; CS6.2-66HB datasheet v1.5, checked 22 October 2026.
- DMEGC: DMxxxG12RT-B66HSW datasheet, document ID dated 15 September 2026, checked 22 October 2026.
- Aiko: Comet 3N72 datasheet, 202608 V1.1; Comet 3N72 product page, checked 22 October 2026.
- LONGi: LR8-66HVD datasheet page, checked 22 October 2026.
Common questions
Do solar panels stop working after 25 years?
No. The 25 to 30 years in guidance and on warranties is the period over which output is warranted, not a failure date. Modules keep generating at a lower level, and the warranty lines on these sheets leave about 85% to 90% of nameplate at year 30. Whether to keep an array depends on the roof, the inverter and the building.
Does degradation differ between PERC and TOPCon panels?
On warranty terms, yes: Canadian Solar's PERC sheet allows up to 2% in the first year and 0.45% a year, against up to 1% and 0.35% on its TOPCon sheet. The NREL fleet study found loss rates did not differ much by module technology, though the summary gives no separate n-type result. The warranty gap is a ceiling, not a measured result.
Should inverter replacement be in a commercial solar business case?
It should be either replacement or an extended warranty. Energy Saving Trust's household guidance says to replace an inverter after around 12 years, and SMA's Sunny Tripower 125 page gives a 5-year standard warranty extendable to 10, 15 and 20 years. A model with no inverter event over 25 years leaves out a likely mid-life item.
Is the degradation rate in a yield model the same as the warranty rate?
Not necessarily. A yield model applies its own assumed annual loss, and PVGIS sets its recommended 14% system loss considering ageing as well as other losses. Ask which degradation assumption a model uses, whether it is the warranty ceiling or a lower figure, and whether ageing is counted once.