Solar Panel Warranty Guide: Compare Coverage by Brand
A solar system is a 25-year investment, and the warranty behind it matters just as much as the panels on your roof. This guide breaks down the four types of solar warranties, compares coverage from major brands, and shows you exactly what to look for before you sign.
Types of Solar Warranties
Equipment / Product Warranty
25 years typical
Covers manufacturing defects and material failures in the solar panels themselves. Guarantees a minimum power output over the warranty period, usually 80% of rated output at year 25.
- ✓Protects against manufacturing defects and premature component failure
- ✓Covers cracked cells, delamination, junction box failures, and frame defects
- ✓Provided by the panel manufacturer, not the installer
- ✓Typically requires panels to be installed by a certified professional
Performance / Power Warranty
25-30 years
Guarantees that your panels will produce a minimum percentage of their rated output over time. Typically 90% at year 10 and 80% at year 25, though premium brands offer better guarantees.
- ✓Defines the maximum allowable degradation rate per year
- ✓Premium panels degrade at 0.25-0.3% per year vs. 0.5-0.7% for standard panels
- ✓Claims require independent testing to verify underperformance
- ✓Does not cover external factors like shading from new tree growth
Inverter Warranty
12-25 years
Covers inverter failures and replacements. String inverters typically carry 12-15 year warranties, while microinverters from brands like Enphase offer 25-year coverage.
- ✓String inverters: 12-15 year standard warranty, often extendable to 20-25 years
- ✓Microinverters: 25-year warranty standard from most manufacturers
- ✓Power optimizers: typically match the panel warranty at 25 years
- ✓Inverter replacement costs $1,000-$2,500 without warranty coverage
Workmanship / Installation Warranty
10-25 years
Covers installation-related issues including roof leaks, wiring problems, and mounting failures. This warranty comes from your installer, not the equipment manufacturer, and varies widely.
- ✓Covers roof penetrations, flashing, and waterproofing around mounts
- ✓Includes electrical connections, conduit runs, and wiring integrity
- ✓Protects against racking and mounting hardware failures
- ✓Only as strong as the installer behind it - choose an established company
Warranty Comparison by Brand
SunPower
Product Warranty
25 years (complete system)
Output at Year 25
92%
Inverter Warranty
25 years (included)
Industry-leading complete coverage including labor
REC
Product Warranty
25 years
Output at Year 25
92%
Inverter Warranty
Varies by inverter brand
Top-tier performance guarantee matching SunPower
LG
Product Warranty
25 years
Output at Year 25
90.6%
Inverter Warranty
Varies by inverter brand
Strong product warranty with excellent degradation rate
Panasonic
Product Warranty
25 years
Output at Year 25
90.76%
Inverter Warranty
Varies by inverter brand
Premium HIT cells with low temperature coefficient
Q Cells
Product Warranty
25 years
Output at Year 25
86%
Inverter Warranty
Varies by inverter brand
Solid mid-range warranty with competitive pricing
Canadian Solar
Product Warranty
25 years
Output at Year 25
83.1%
Inverter Warranty
Varies by inverter brand
Budget-friendly option with standard warranty terms
Trina Solar
Product Warranty
25 years
Output at Year 25
83.1%
Inverter Warranty
Varies by inverter brand
Large global manufacturer with standard coverage
Tesla
Product Warranty
25 years
Output at Year 25
80%
Inverter Warranty
25 years (Tesla inverter)
Integrated system warranty when paired with Tesla inverter
What to Look For in a Solar Warranty
1.Check if the warranty is transferable
A transferable warranty adds value to your home if you sell. Most manufacturer warranties transfer automatically, but some require notification or a small fee. Workmanship warranties from installers may or may not transfer. Confirm this before signing your contract, as it directly affects your home's resale value.
2.Understand the difference between product and performance warranties
The product warranty covers physical defects in the panel itself (cracked glass, failed junction box). The performance warranty guarantees a minimum energy output over time. You could have a panel that is physically intact but producing below its guaranteed output, which would fall under the performance warranty, not the product warranty.
3.Ask about the workmanship warranty separately
Many homeowners assume the installer's workmanship warranty matches the panel warranty, but it is often much shorter (sometimes only 1-5 years from budget installers). A roof leak caused by a poor installation at year 8 would not be covered by a 5-year workmanship warranty. Look for at least 10 years, and preferably 25.
4.Verify the installer will still be in business
A 25-year warranty is worthless if the company goes bankrupt in year 3. Research the installer's financial stability, years in business, and number of installations completed. Look for established companies with a strong local presence. Some installers also back their warranties with third-party insurance for added protection.
5.Read the fine print on exclusions
Most solar warranties exclude damage from severe weather events (hurricanes, hail beyond a certain size), acts of God, improper maintenance, unauthorized modifications, and power surges. Some void the warranty if panels are cleaned with abrasive materials or high-pressure washers. Know exactly what is and is not covered.
6.Keep all documentation and register your warranty
Save your purchase contract, installation completion certificate, inverter serial numbers, and panel serial numbers. Many manufacturers require online warranty registration within 30-60 days of installation. Failing to register can make the claims process much harder or even void certain coverage.
Frequently Asked Questions
What is a solar panel warranty?
A solar panel warranty is a guarantee from the manufacturer or installer that covers defects, performance degradation, and installation issues for a specified period. Most solar systems come with multiple warranties: a product warranty covering physical defects (typically 25 years), a performance warranty guaranteeing minimum energy output (25-30 years), an inverter warranty (12-25 years), and a workmanship warranty from the installer covering the installation itself (10-25 years).
How long do solar panel warranties last?
Solar panel product warranties typically last 25 years, covering manufacturing defects and material failures. Performance warranties also run 25-30 years, guaranteeing minimum power output (usually 80-92% at year 25 depending on the brand). Inverter warranties range from 12 years for string inverters to 25 years for microinverters. Workmanship warranties from installers vary the most, ranging from 1 year to 25 years depending on the company.
What voids a solar panel warranty?
Common actions that void a solar panel warranty include unauthorized modifications or repairs, improper installation by an uncertified installer, physical damage from impacts or improper cleaning (such as pressure washing), failure to register the warranty within the required timeframe, and removing or relocating panels without manufacturer approval. Natural disasters and extreme weather events are also typically excluded from coverage.
Are solar warranties transferable?
Most solar panel manufacturer warranties are transferable to new homeowners when you sell your property, often automatically or with a simple notification to the manufacturer. However, installer workmanship warranties may or may not transfer depending on the company's policy. Some installers charge a transfer fee or require the new owner to agree to certain terms. Always confirm transferability before signing your contract, as it directly impacts your home's resale value.
What's the difference between a product warranty and a performance warranty?
A product warranty (also called an equipment or materials warranty) covers physical defects in the solar panel such as cracked cells, delamination, faulty junction boxes, and frame corrosion. A performance warranty (also called a power output warranty) guarantees the panel will produce a minimum percentage of its rated wattage over time, typically 90% at year 10 and 80-92% at year 25 depending on the brand. You could have a panel with no physical defects that still underperforms its guarantee, which would be a performance warranty claim.
Related Solar Resources
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