How to Read a Solar Warranty (2026): Panels, Inverter and Workmanship

Quick answer: A rooftop solar system comes with several warranties, not one. The panels carry a product warranty against defects (at least 10 years) and a power output warranty (25 years) under MNRE's May 2026 rules for subsidised schemes. The inverter has its own product warranty (at least 8 years for inverters enlisted under PM Surya Ghar). The installer covers workmanship, and under PM Surya Ghar must warrant the whole system for five years from commissioning. For each one, check who gives it, the date it starts, what it excludes and how you claim.

"25-year warranty" is the line most solar quotes lead with. It is true, but it describes only one of the promises you are buying, and not the one you are most likely to use. Here is how to read the warranty papers for a home rooftop system, with the rules that apply in 2026.

The warranties on a rooftop solar system

The first three come from manufacturers and are only as good as the paperwork that links them to your roof. The fourth comes from the company that installed the system, and it is usually the first one you call.

Panels: two warranties on one sheet

A module warranty sheet holds two separate promises.

• The product warranty covers defects: a cracked cell from manufacturing, a failed junction box, delamination. MNRE's Standard Operating Procedure on module warranties, issued by Office Memorandum on 6 May 2026, sets a minimum of 10 years for manufacturers supplying PM Surya Ghar, PM KUSUM and other distributed renewable energy schemes.
• The power output warranty promises that the panel will still produce at least a stated share of its rated power for 25 years. It does not mean 25 years of free replacement. A claim is accepted only when measured output falls below the guaranteed level after manufacturer tolerances and measurement uncertainty are allowed for. Read the actual output figures printed in your warranty sheet, not just the number of years.

Watch the start date. Under the SOP, the warranty runs from installation or commissioning, provided the modules reach your site within six months of the manufacturer's invoice. If they sit in a warehouse longer, the warranty is cut in proportion to the delay. Ask your installer for the module invoice date as well as the serial numbers.

The inverter: a shorter warranty on a harder-working part

The inverter converts the panels' DC power into AC for your home and runs electronics every day the sun is up. Inverters enlisted under PM Surya Ghar must carry a product warranty of at least eight years from commissioning. That is well short of the panels' 25 years, so plan for at least one inverter replacement over the life of the system, and ask whether the manufacturer offers a paid extension.

Check that the inverter's serial number appears on your warranty documents and that you can see its generation data on the display or the manufacturer's app. Both matter when you make a claim.

Workmanship and the system warranty

Most problems in the first years are not a faulty panel. They are a loose connector, water at a roof penetration, a tripping breaker or a structure that needs tightening. That is workmanship, and it is the installer's responsibility.

Under PM Surya Ghar, the vendor must give a warranty on the entire rooftop system for five years from commissioning, a rule set out in REC's vendor framework of November 2024. MNRE's October 2026 instructions to vendors go further: when a third-party field inspection finds a defect, the vendor has 15 days to fix it and upload geo-tagged, time-stamped proof on the National Portal, and the OEM warranty documents must carry the correct serial numbers of the panels and inverter.

For a system bought outside the scheme, workmanship cover is whatever your contract says. Get it in writing, with the period and the response time.

How a panel warranty claim works

The May 2026 SOP also standardises how manufacturers handle claims for scheme-supplied modules.

If a claim is disputed, testing is done at an NABL-accredited laboratory. The cost is first shared 50:50 between the manufacturer and the consumer, and the side found to be wrong pays the full amount.

Claims can be refused for installation that ignores the manual or uses substandard mounting structures, unauthorised repairs, tampered serial numbers, glass broken by external damage, and natural disasters such as floods, earthquakes and cyclones. Home insurance is what covers storm damage, so check that your policy includes the rooftop system.

Solar water heaters: why one product carries two numbers

The same reading habit applies to solar water heaters. At Greentek, the flat plate collectors carry a 5 year warranty and the solar water heater carries 1 year. The collector is copper, which is stable. The storage tank is stainless steel or mild steel, and its life depends on the quality of the water it holds, which differs from home to home. So the tank cannot honestly carry as long a warranty as the collector. On solar power plants, our warranty follows the OEM terms of the panels and inverter supplied.

A checklist before you sign

1. List every warranty separately: panel product, panel output, inverter and workmanship, each with its period and the name of whoever gives it.
2. Get the start dates in writing, along with the module invoice date and the commissioning date.
3. Match serial numbers for every panel and the inverter on the warranty documents.
4. Read the exclusions, especially installation, mounting structure and weather.
5. Know the claim route: the installer's contact, and the manufacturer's portal, phone or WhatsApp line.
6. Keep one folder with the invoice, warranty certificates, commissioning report and O&M manual.

Frequently asked questions

Does a 25-year panel warranty mean free replacement for 25 years?

No. The defect warranty is shorter, at least 10 years under the SOP. The 25-year promise is about power output: a claim succeeds only if measured output falls below the guaranteed level.

Who do I call first if generation drops?

Your installer. Most drops come from wiring, a tripped breaker, shading or dirt, which the installer checks before a manufacturer claim is raised.

Is storm or flood damage covered?

Not by the manufacturer. The SOP excludes natural disasters, so cover the system under your home insurance.

Warranty rules and scheme guidelines can be revised. This guide is current as of October 2026; always read the warranty documents issued for your own system.

Want a second look at a quote's warranty terms?

Greentek's Secunderabad team has worked in solar since 1997. If you are comparing rooftop or solar water heater quotes, share them with us and we will walk you through what each warranty covers.