A solar panel system is a significant investment — typically £7,000 to £14,000 for a three to four bedroom home in the UK — and one that’s supposed to last 25 to 30 years. So it’s worth understanding exactly what protection you have if something goes wrong, because the warranty and insurance landscape is more complicated than most installers explain during the sales process.
The Three Layers of Protection
There are three separate things protecting your solar installation, and they’re often conflated:
Product warranty covers manufacturing defects in the panels themselves. Most quality panel manufacturers (Jinko, Longi, Canadian Solar, SunPower) offer a 12-year product warranty covering defects in materials and workmanship, plus a separate 25 or 30-year performance guarantee (more on that below). Inverter warranties typically run 5 to 12 years, with extended warranties purchasable from the manufacturer.
Workmanship warranty covers the quality of the installation — how the panels are mounted, how the cabling is run, whether the roof penetrations are properly sealed. This comes from your installer, not the manufacturer, and is typically 2 to 5 years. This is the most variable protection and the one most at risk if your installer goes out of business.
Home insurance is where most people assume they’re covered and often aren’t, or not in the way they think. More on this shortly.
Performance Guarantees: Read the Small Print
A 25-year performance guarantee sounds reassuring, but it’s worth understanding what it actually promises. Most manufacturers guarantee that panels will produce at least 80% to 87% of their rated output after 25 years. That’s a guarantee against degradation beyond a specified rate — it doesn’t mean the manufacturer will send someone to fix your panels if they underperform due to shading, soiling, or a faulty inverter.
Claiming on a performance guarantee also requires proof that your system is genuinely underperforming relative to spec, which means having monitoring data and being able to demonstrate the shortfall isn’t attributable to external factors. In practice, manufacturer performance guarantee claims are rarely straightforward.
What the performance guarantee is genuinely useful for: protection against panels that degrade significantly faster than expected, which does happen occasionally with lower-quality products. For this reason, choosing panels from manufacturers with long and verifiable track records matters more than the guarantee period printed on the spec sheet.
The Installer Insolvency Problem
Here’s the thing most homeowners don’t think about when they sign with a solar installer: the UK solar industry has a mixed track record of business longevity. A number of installers who were actively selling in 2020 to 2023 no longer exist. If your installer goes bust, your workmanship warranty is effectively worthless — there’s no one to call.
MCS certification provides one layer of protection here. MCS-certified installers are required to participate in a consumer protection scheme (currently the RECC or the MCS Complaints Resolution Service) that provides some recourse even if the installer closes. However, this protection has limits and doesn’t automatically guarantee you’ll get remediation work done.
Before signing: check that your installer holds current MCS certification (verify at mcscertified.com, not just by taking the installer’s word), check whether they participate in a deposit protection or insurance-backed guarantee scheme, and check Companies House to see how long the business has been trading. A solar company that’s been operating for more than five years is meaningfully lower risk than a year-old startup, however impressive their sales material looks.
Insurance-backed guarantees (IBGs) are a separate product that some installers offer — a policy from a third-party insurer that covers workmanship defects even if the installer goes bust. These typically cost £150 to £300 and are absolutely worth it if your installer offers them. If an IBG isn’t mentioned, it’s worth asking.
Home Insurance: Check Your Policy Before You Assume
Adding solar panels to your home changes your insurance situation in a few ways that most policies don’t automatically handle.
First, the system adds value to your home that your buildings insurance policy needs to reflect. Most policies cover permanently attached structures as part of the building sum insured, but if you haven’t updated your sum insured since installation, you may be underinsured. An 8kW system with battery storage adds £15,000 to £20,000 to your rebuild cost — worth checking your sum insured reflects this.
Second, some insurers require notification of solar installation. Failure to notify could invalidate a claim. Check your policy terms or call your insurer.
Third, damage to panels themselves varies by insurer. Most buildings policies cover storm damage, but accidental damage cover is often excluded unless you’ve specifically added it. If a panel is cracked during roof maintenance work or by a falling branch, you want to confirm whether that’s covered.
Specialist solar insurance is available and worth considering if your system includes battery storage with significant capacity. Some specialist providers offer all-risks cover specifically for renewable energy systems, covering panel damage, inverter failure, and generation loss during repairs. For larger systems — particularly anything commercial scale — this is worth a conversation with a specialist broker.
What Good Protection Looks Like
Put together, the protection you want for a UK solar installation looks like this: panels from an established manufacturer with a 12+ year product warranty and 25-year performance guarantee; an MCS-certified installer with an IBG covering their workmanship; buildings insurance updated to reflect the system’s value; and a monitoring system that gives you actual generation data so you can identify underperformance early.
That combination won’t protect against every scenario, but it addresses the main failure modes: manufacturing defects, poor installation, installer insolvency, and physical damage. The monitoring piece is often overlooked — a system that’s producing 40% less than expected due to a faulty string can go unnoticed for years without it.
Most decent installers will talk through these protections as part of their pre-sale process. If yours doesn’t bring it up, that’s worth noting before you sign anything.