A solar panel warranty covers two separate things, and you need both
When you buy solar panels, the warranty is not a single promise. It is two distinct guarantees from the manufacturer. The first is the product warranty, also called the equipment warranty. This covers manufacturing defects and premature failure of the panels themselves. The second is the performance warranty, also called the power output warranty. This guarantees the panel will produce at least a certain percentage of its original rated output over time.
A solar panel warranty in 2026 typically lasts 25 years for product coverage and 25-30 years for performance, guaranteeing at least 80-87% output. You need both in writing from the manufacturer, not just a verbal promise.
- Get both a product and a performance warranty in writing.
- Tier-1 manufacturers offer 25-year product warranties in 2026.
- Performance warranties guarantee 80-87% output after 25 years.
- Budget panels may have only 10- to 12-year product warranties.
- Check the MCS Product Directory to verify warranty terms.
- A solar panel warranty covers two separate things, and you need both
- The standard product warranty length is 25 years, but shorter terms still exist
- The performance warranty guarantees at least 80-87% output after 25 years
- Quick numbers, warranty terms for typical 2026 residential solar panels
- The installer’s workmanship warranty is separate and typically shorter
- The answer to "what should I look for in a solar panel warranty in 2026" is a 25-year product warranty plus a 25-year performance warranty from a manufacturer with UK-based support
- How to verify an installer is certified to install your warranted panels
In 2026, most tier-1 manufacturers offer a 25-year product warranty and a 25–30 year performance warranty, according to MCS (Microgeneration Certification Scheme) published installer standards and manufacturer spec sheets referenced on the MCS Product Directory (MCS Product Directory, 2026). You should verify both warranties are written into the contract, not just verbally promised. A verbal promise has no legal weight if the manufacturer disputes a claim years later.
The standard product warranty length is 25 years, but shorter terms still exist
As of 2026, 25 years is the industry norm for tier-1 solar panel product warranties from manufacturers like Longi, JinkoSolar, Trina Solar, and Canadian Solar. These panels dominate the UK residential market. Some budget or off-brand panels carry only 10- or 12-year product warranties, as shown by filtering the MCS Product Directory by warranty term (MCS Product Directory, 2026).
A shorter product warranty often indicates lower-quality manufacturing and reduces the panel’s resale value if you sell your home within the warranty period. Buyers and mortgage lenders increasingly check warranty terms. The product warranty covers repair or replacement of panels that fail due to materials or workmanship, not damage from weather, installation error, or external impact. That distinction matters if a storm or a poorly fitted roof tile damages a panel.
The performance warranty guarantees at least 80-87% output after 25 years
The standard performance warranty for tier-1 panels in 2026 guarantees at least 84% of original rated power after 25 years, with some premium models guaranteeing 87% (Manufacturer datasheets on the MCS Product Directory, 2026). The warranty typically guarantees 97% output in year 1, then a linear degradation of no more than 0.5%–0.6% per year. If output drops below the guaranteed level, the manufacturer must replace or compensate for the underperforming panels.
Performance warranties are backed by the manufacturer, not the installer, so the manufacturer’s financial stability matters. If the manufacturer goes bust, the performance warranty is effectively worthless. Stick to manufacturers with a long trading history and a UK-based service network. The Energy Saving Trust advises checking that the manufacturer has a UK office or authorised service partner for warranty claims (Energy Saving Trust, 2026).
Quick numbers, warranty terms for typical 2026 residential solar panels
| Warranty type | Tier-1 panel (standard) | Budget panel (common minimum) |
|---|---|---|
| Product warranty length | 25 years | 10 years |
| Performance warranty length | 25 years | 25 years |
| Year-1 output guarantee | 97% of rated power | 95% of rated power |
| Year-25 output guarantee | 84% of rated power | 80% of rated power |
| Annual degradation cap | 0.55% linear | 0.65% linear |
Source: MCS Product Directory, manufacturer datasheets for top-10 selling panels in the UK (2026 Q1 data).
The installer’s workmanship warranty is separate and typically shorter
In the UK, a reputable MCS-certified installer (required for Smart Export Guarantee eligibility) usually offers a 10-year workmanship warranty covering installation defects, roof penetrations, and wiring (MCS Installation Standards MIS 3002, 2026). A workmanship warranty is a contract between you and the installer, not the manufacturer. If the installer goes out of business, this warranty may be worthless.
To protect against installer insolvency, check whether the installer is backed by a warranty insurance scheme (e.g., the Home Insulation & Energy Systems Quality Assured Guarantee, or a similar insurance-backed guarantee). The workmanship warranty does not cover the panels themselves, that is the product warranty. So you need both: a strong product warranty from the manufacturer and a solid workmanship warranty from the installer.
The answer to “what should I look for in a solar panel warranty in 2026” is a 25-year product warranty plus a 25-year performance warranty from a manufacturer with UK-based support
The single most important factor is the product warranty term: 25 years is the minimum you should accept for a residential system in 2026. The performance warranty should guarantee at least 84% output after 25 years, with linear degradation of no more than 0.55% per year. The manufacturer must have a UK-based warranty claims process and a UK office or authorised service partner, otherwise claiming under warranty may be impractical (MCS guidance on manufacturer service requirements, 2026). The installer’s workmanship warranty should be at least 10 years and ideally insurance-backed.
If you are comparing quotes, ask for the exact warranty terms in writing before you sign. Do not rely on brochures or sales pitches. compare solar panel brands and their warranty terms
How to verify an installer is certified to install your warranted panels
The installer must be MCS-certified for the system to be eligible for the Smart Export Guarantee and for most warranty claims to be valid (MCS website, “Find an Installer” tool, 2026). The installer should also be TrustMark-registered, which is the UK government-endorsed quality scheme for home improvements (TrustMark website, 2026). For electrical work, the installer should be registered with NICEIC or NAPIT (competent person schemes for Part P compliance) (GOV.UK, competent person schemes for electrical work, 2026).
You can check a specific installer’s MCS certificate number on the MCS website and confirm they are listed for the specific panel brand you are buying. The panel manufacturer’s warranty often requires installation by an MCS-certified installer to remain valid, confirm this in the warranty terms before signing. how to choose a solar panel installer
Frequently Asked Questions
Most tier-1 manufacturers offer a 25-year product warranty and a 25- to 30-year performance warranty, according to MCS published installer standards and the MCS Product Directory as of 2026.
No, the manufacturer warranty covers defects in materials or workmanship, not installation errors. Installation is covered by a separate workmanship warranty from the installer, typically 5 to 10 years, as advised by MCS.
The product warranty covers repair or replacement of panels that fail due to manufacturing defects. The performance warranty guarantees the panel will produce at least a set percentage of its rated output, often 80-87% after 25 years, as specified by the manufacturer.
Once the warranty expires, you pay for repair or replacement yourself. Some installers offer extended warranties for an extra cost, but these are not standard. The Energy Saving Trust recommends budgeting for potential replacement after 25-30 years.
Yes, all new solar panels sold in the UK come with a manufacturer warranty. By law, consumers have rights under the Consumer Rights Act 2015, but the specific warranty terms are set by the manufacturer and vary by brand.
Most tier-1 manufacturers allow transfer of the warranty to a new homeowner, but terms vary. Check the original warranty document; some require notification within 30 days of transfer, as noted by MCS installer guidelines.
