A solar system is a 25-30 year investment, so the warranty terms matter as much as the yield. There are several independent warranties, and it is worth knowing each one.
1. Product warranty (panel)
The manufacturer guarantees the panel is free of material and workmanship defects. Premium manufacturers (for example JA Solar) give 12-15 years, with longer terms on some products. It covers replacing a defective panel, but not consequential damage, and not always the removal and shipping costs. Read who bears these.
2. Performance warranty
The manufacturer guarantees the panel will still deliver a defined share of nameplate power years later. Typically 97-98 percent at the end of year one, then a 0.4-0.55 percent annual decline, reaching 80-88 percent after 25-30 years. If measured output falls below the value, the manufacturer compensates or replaces. This requires documented measurement, so keep the initial test report.
3. Inverter warranty
The inverter is the component most likely to fail. The base warranty is 5-10 years depending on the maker: Huawei, Fronius and others usually offer 5-10 years, with paid extensions (for example to 12-20 years). A 10 year warranty is very good value, but the manufacturer's conditions (operating temperature, communication, professional installation) must be met. Batteries typically carry 10 years too, or a commitment by throughput (MWh) and remaining capacity (for example 70 percent).
4. Installer warranty
The installer is responsible for defects in the mounting, roof penetrations, cabling and structure. Alongside statutory liability, the committed period is typically 2-5 years. This matters most in practice, because most faults come from installation rather than the product. Ask what is guaranteed for roof watertightness and who is liable if the installer ceases to exist.
5. Insurance
- Home insurance add-on: many insurers treat the solar system as part of the building, but it must be declared separately with its value. If it is not reported, a claim can be disputed.
- Hail, storm, lightning: normally covered, but conditions differ (excess, maximum sum).
- Theft, vandalism: may need a separate add-on.
- Business interruption: for commercial systems, consider insuring lost generation too.
Hail
Panels pass a 25 mm ice ball test at 23 m/s (IEC 61215), but larger hail can cause damage. Manufacturer warranties typically do not cover hail damage, so insurance must. After damage, take photos, notify the insurer, and do not repair before the loss assessment.
Quick checklist
| Warranty | Typical term | What to check |
|---|---|---|
| Panel product | 12-15 years | Replacement and labour |
| Performance | 25-30 years | Measurement conditions |
| Inverter | 5-10 years | Extendability |
| Installer | 2-5 years | Watertightness, liability |
Get warranties in writing, and keep datasheets, the invoice and the test report. SolarBay hands all of this over at installation, and its annual inspection helps document warranty claims.
What to do in case of a claim
First, safely shut the system down (AC breaker, then DC isolator) if this can be done without danger. Do not touch damaged panels or cables, as the DC side is live in daylight. Take photos, report the damage to the insurer and notify the installer. The installer can document the cause of damage and the previous state of the system with a report, which speeds up settlement. Wait for the loss assessment before repairing, and use only a qualified technician.
