solar panel warranty explained

Read on to understand everything you need to know about securing your solar investment.

What does a solar panel warranty include?

What each brand still guarantees at the end of the warranty period, as a percentage of original capacity.

A solar panel warranty includes coverage for product quality, performance assurance, and protection against installation mistakes. Each warranty targets specific risks affecting your solar system’s reliability and longevity.

The main types of warranties are:

Product warranty - protects against manufacturing defects and material failures.
Performance warranty - ensures the system maintains a certain power output over time.
Installation warranty - covers errors in workmanship, including wiring and mounting faults.

What does the product warranty cover?

The product warranty addresses defects arising from manufacturing issues, such as cracked solar cells, damaged junction boxes, or panel delamination. Manufacturers typically offer repair or replacement within 10 to 25 years, depending on the panel’s quality.

What guarantees does the performance warranty provide?

The performance warranty ensures panels retain between 80% and 90% of their initial power output after 25 years. Panel degradation usually follows a steady pattern, with about 3% power loss in the first year and 0.3% to 0.7% loss annually after that.

How long does a solar panel warranty last?

Solar panel warranties vary by type and component but commonly range from 10 up to 30 years. Product warranties generally last 10 to 15 years, while performance warranties extend to 25 or 30 years.

Here are typical warranty durations for key components:

Solar panels product warranty: 10 - 25 years
Solar panels performance warranty: 25 - 30 years
String inverter warranty: 10 - 15 years
Microinverter warranty: up to 25 years
Installation workmanship warranty: 1 - 10 years

Which solar panels include a 25 year warranty?

Most modern solar panels come with a 25 year performance warranty by default. Premium panels extend this coverage to 30 years, maintaining higher output levels, often close to 90%, throughout the warranty period.

Does the size of the system affect warranty terms?

A 3kW solar system follows the same warranty structure as larger systems. Product warranties remain between 10 and 25 years, and the performance warranty typically extends up to 25 years, regardless of system size.

What costs are associated with solar panel warranties and extended coverage?

The standard solar panel warranty is usually included in the overall system price. However, opting for extended warranties or additional coverage like inverter protection or insurance will add to your costs.

Typical additional costs include:

Extended inverter warranty: €200 - €800 incl. VAT
Full system insurance: €100 - €300 annually
Performance monitoring tools: €150 - €400 incl. VAT

Example cost calculation for a fully protected solar system

For a system with 10 panels that includes extended warranty coverage, the cost breakdown might be:

Panels: 10 × €250 = €2,500
Inverter: €1,200
Installation: €2,000
Extended warranty: €500
Total: approximately €6,200 incl. VAT

This total cost aligns with a complete solar panel system overview and may vary depending on specific installation details.

How does the solar panel warranty claim process work?

To submit a solar panel warranty claim, start by identifying the problem and contacting your installer or the manufacturer. Having the correct documentation is vital to gaining approval.

Steps to file a solar panel warranty claim

Verify your system’s performance through monitoring data.
Contact your installer to perform an inspection.
Gather necessary documents such as invoices, warranty certificates, and photos showing the issue.
Submit your claim to the manufacturer or installer.
Allow time for inspection, approval, and resolution.

Why might warranty claims be rejected?

Claims can be denied due to improper installation, physical damage caused by the owner, or lack of required documentation. Actions like walking on the panels or incorrect mounting may void warranty coverage entirely.

What common problems arise with solar panel warranties?

Solar panel warranty difficulties often result from installer mistakes, ambiguous warranty terms, or challenges in verifying system underperformance.

Common issues encountered include:

Claims rejected due to installation errors
Unclear coverage for labor-related costs
Challenges in proving system underperformance
Delays in manufacturer response or service

How can you reduce warranty problems?

Choosing certified and experienced installers and consistently monitoring your system’s performance can greatly minimize warranty disputes. Professional installation and regular checks through expert solar services help ensure claims are handled smoothly.

Which factors determine the strength of a solar panel warranty?

The best solar panel warranty depends on warranty length, degradation rates, coverage details, and the manufacturer’s reputation for reliability.

What does the 20% rule mean in solar warranties?

The 20% rule guarantees that panels will retain at least 80% of their original output after 25 years. This sets a clear benchmark for acceptable degradation and warranty eligibility.

What makes a solar panel warranty strong?

A robust warranty offers long product coverage periods, predictable and low degradation rates - ideally below 0.5% annually - and compensation for labor costs. Panels manufactured with N-type cells generally degrade more slowly compared to P-type cells, contributing to stronger warranty terms.

Before selecting a system, review different solar panel options to compare warranties and ensure a reliable long-term investment.

Selecting the right solar panel warranty involves more than just looking at the coverage length. You should consider performance guarantees, the quality of installation, and clear claim conditions. A dependable solar system combines strong product protection with predictable degradation over time. To avoid unexpected issues, compare multiple offers and ask for detailed warranty terms through Soleva. This approach will help you secure a system that delivers reliable energy output for decades.

Frequently Asked Questions

How long is a solar panel warranty?

Solar panel warranties typically last 10 to 15 years for product defects and 25 to 30 years for performance guarantees. The performance warranty ensures the panels maintain a minimum output level, while the product warranty covers physical panel defects. Together, these warranties define the system’s expected reliability and financial value over time.

Which solar panels have a 25 year warranty?

Most current solar panels come standard with a 25 year performance warranty. Premium models may extend this up to 30 years and maintain higher power output throughout the period. The variance rests mainly in degradation rates and the quality of materials used.

What is the 20% rule for solar panels?

The 20% rule states that solar panels should retain at least 80% of their original energy output after 25 years. This threshold defines acceptable degradation, and panels performing below this level typically qualify for warranty claims under performance guarantees.

What is the cost of extending a solar panel warranty?

The price to extend a solar panel warranty varies depending on the components covered. Inverter warranty extensions usually cost a few hundred euros, while full system coverage, including labor and damage insurance, will be more expensive. These extensions provide additional peace of mind by reducing long-term maintenance costs.

How does the solar panel warranty claim process function?

To claim under your solar panel warranty, start by confirming system performance issues. Then, contact your installer and provide necessary documents such as purchase receipts and warranty certificates. After an inspection, the manufacturer will decide whether to repair, replace, or compensate for the faulty components according to the warranty terms.

Indicative prices for the Belgian market, checked in August 2026 against energy-village.be, thuisbatterij.be and zen-zonne-energie.be. These are market ranges for an installed system including VAT, not a quotation: your price depends on capacity, brand and the state of your existing installation.