Solar Panel Warranty Explained: What 25 Years Covers

Short answer: a "25-year solar panel warranty" is usually a performance warranty: the manufacturer promises the panel will still give a set share of its rated power, often 80-87% after 25-30 years. Manufacturing defects are covered by a separate product warranty, typically 10-15 years. The inverter has its own 5-10 year warranty, and the installer's workmanship warranty covers the structure, wiring and leaks. Knowing which warranty covers what saves you money and arguments later.

Terms vary by brand and model. Always read the warranty document for the exact panel model in your quote. General guide as of October 2026.

The 4 Warranties in a Solar System

Many buyers only hear "25 years" and assume everything is covered for 25 years. It is not, so get all four in writing.

Performance Warranty: What "80% After 25 Years" Means

Every panel slowly loses output, called degradation. A typical modern warranty looks like this:

Illustrative figures; check the datasheet of your exact model. TOPCon panels usually carry a better degradation guarantee.

In units: a 3kW system making 13 units a day in year one should still make about 11 units a day around year 25. If your panels fall well below the guaranteed curve (after accounting for dust, shade and weather), that is a valid performance claim.

Product Warranty: Defects You Can Claim

Covered (typical):

• Delamination (layers separating) or bubbles inside the glass
• Junction box or connector failure
• Frame corrosion beyond normal limits
• Cell cracks or hot spots from manufacturing defects
• Glass breakage without any impact

Not covered (typical):

• Damage from cyclones, lightning, falling coconuts or branches
• Cracks from people walking on panels
• Damage from wrong installation (drilling frames, wrong clamps)
• Salt corrosion on a structure (that is the installer's area, not the panel maker's)

Inverter Warranty

The inverter is the part most likely to fail in 25 years. A good inverter lasts 10-12 years, so plan for one replacement. Check:

• Warranty length and whether an extension is available
• Is the warranty replacement or repair?
• Does a local service partner exist in Cuddalore, or must it be shipped?

More: best on-grid solar inverter in India.

Workmanship Warranty: The One That Matters Locally

Most problems in coastal Tamil Nadu come from installation, not panels:

• Rusted bolts and structures from salt air
• Loose DC connectors causing heating
• Water leaks where the structure is anchored
• Poor earthing

Ask your installer for a written workmanship warranty and what it covers. Choose hot-dip galvanized structures and three earthing pits: coastal structure guide, solar earthing guide.

Warranty Comparison by Brand (What to Ask)

Big Indian brands like Tata Power Solar, Adani, Waaree, Premier and Exide all offer long performance warranties, but the product warranty years and degradation rate differ by model. When you compare quotes, ask for:

1. Product warranty years (10, 12 or 15?)
2. Guaranteed output at year 25 and year 30
3. First-year and yearly degradation limits
4. Who handles claims in Tamil Nadu

Brand comparisons: Waaree vs Adani vs Tata, best solar panel brands in Tamil Nadu.

How to Make a Warranty Claim

1. Keep the invoice with every panel serial number listed (also needed for the subsidy).
2. Note the problem: monitoring app data showing low units, photos of the damage, error codes.
3. Call your installer first. They test the system and confirm it is a manufacturing issue, not dust or shade.
4. The installer raises the claim with the manufacturer with test reports.
5. Replacement or repair, depending on the warranty terms.

Tip: an installer who is an authorised partner of the brand can process claims faster. We are an official partner of TATA Power Solar and Exide.

6 Things That Void Your Warranty

Safe cleaning: solar maintenance guide.

Add Insurance for Cyclones and Lightning

Warranties do not cover natural disasters. Add the solar system to your home insurance for storm, flood, lightning and theft. It costs little compared with the system value, and in Cuddalore's cyclone belt it is worth it. See solar panels in rain and cyclones.

Clear Warranties, in Writing

Every quote from us lists the panel model, DCR status, performance and product warranty, inverter warranty and our workmanship cover, and we handle claims locally from Kondur, Cuddalore. Call or WhatsApp +91 7904369094 or check your subsidy with the eligibility checker.