Solar PV Knowledge Bank

Solar Panel Guarantees

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solar panel guarantees

How long do solar panels last?

The average lifespan for solar panels is around 25 years, but you can expect most to keep generating electricity after this date (if not at the same rate). Indeed some of the first panels installed in the early 80s are still running.

Before we dive into the details of solar panel guarantees, it’s worth noting that PV modules are statistically very unlikely to fail. In most cases they will continue producing energy for decades without any trouble at all. But it’s always best to be prepared, and know what guarantees are on offer.

Product warranty vs performance warranty

Solar panels typically come with two guarantees: a product warranty and a power warranty.

  • Product warranty - this covers defects in the equipment, for example if it suddenly stops working after a few months due to a fault in the materials or workmanship.
  • Power warranty - this states the expected output of a panel after certain periods of time (eg 5 years, 10 years, 20 years). All PV is affected by gradual degradation in efficiency, so the output will decrease. If the panels do not perform as promised, you may be able to get them replaced or repaired - but some power warranties do not cover defects.

It’s important to be aware of hidden costs. If there is a fault and you need someone to come out, remove old panels, deliver new ones and install them - who pays for this? You or the manufacturer? This varies by warranty, so always check the small print.

How long are the warranties?

Solar panel product warranties usually last 10 years. The power warranties used to be stepped, eg guaranteeing 90% output after 10 years and 80% output after 25 years, but nowadays most companies offer linear degradation warranties (eg 0.7% output loss per year). Some manufacturers like SunPower offer a far superior warranty, guaranteeing a much higher output after 25 years:

sunpower warranty

What happens if the solar panel company goes bust? Since solar is a relatively new and fast-growing market, there is a chance that the manufacturer of your system components might go out of business during the 25 year warranty time. In that case, the warranty may be covered by a third-party insurance, or you’d have to rely on your own insurance (see below).

Guarantees for other parts of the system

Of course the panels are not the only parts that need a guarantee, other components such as the inverter and batteries come with their own.

Inverters have shorter warranties, usually 10-12 years with the option of an extension. You should expect to have one inverter replacement during the life of the system.

Battery warranties are more complex, depending on the type of technology used, and may be based on years of operation or number of cycles. For example, Tesla guarantees Powerwall 2 will be free from defects and retain 80% of capacity after 10 years.

tesla battery

Workmanship warranty

Spirit gives a 5 year workmanship warranty on all domestic installations, backed by HIP. So even if there were a fault in our workmanship and we’d gone out of business, HIP would pay for another installation company to come and sort it out. They would also action any warranty claims with the manufacturer, for example with the panels or inverter, and if necessary swap out these components without cost to you. 

Solar panel insurance

Solar panels will usually be covered by your building insurance, as they are part of the permanent fixtures of the property. It’s always best to check with your insurer (ideally before installation) to make sure. If they won’t insure solar panels, then shop around as plenty of others will! Also be sure to check whether you’re covered for accidental damage as well as theft, vandalism, fire, falling trees etc.

Solar PV maintenance

As static systems, solar PV arrays don’t require much maintenance. If they’re mounted at an angle, they’ll generally clean themselves in the rain, unless you live in a particularly dusty or polluted area. Then it’s worth getting the panels cleaned every few years to ensure they perform at the maximum output (we can do this for you).

Solar systems can also be affected by wildlife, particularly birds nesting underneath, risking damage to the equipment. You can prevent this by installing bird protection, which is most economical to get done when the system is put up. The protection - spikes or mesh - must be specialist so it doesn’t void the system warranty by interfering with the panels themselves.

Solar Panel Bird Proofing

Smart Export Guarantee

On the flipside of performance guarantees, how are you insured a fair payment for any excess solar electricity you send to the grid? The Smart Export Guarantee (SEG) requires large energy companies to offer an export tariff to solar-generating customers. The exact price is down to the company, but it must be positive and to be eligible, the installation must be MCS certified.

Learn more

To find out more about expected returns, system guarantees or what Spirit can offer, download our free guide to residential PV:

Residential Solar PV Guide

15 minutes for everything you need to know about solar PV installations.

Solar Panel Installer Download now

Or reach out to us on 0118 951 4490.

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