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The Sunsave Guarantee: explained

Last updated on 11 April 2024

Get a detailed breakdown of what the Sunsave Guarantee includes, from monitoring & maintenance to insurance.

Photo of author Charlie Clissitt

Written byCharlie Clissitt

Solar panel installer drilling into a mounting bracket on a rooftop, blue filter overlaid, black tick in a yellow box in the centre foreground

As well as launching the UK’s very first solar subscription, Sunsave Plus, we’re also launching the first 20-year aftercare and support package, the Sunsave Guarantee.

Here’s everything you need to know about the Sunsave Guarantee, including what it covers, why it matters, and the headaches it could save you in the long term.

Why did we create the Sunsave Guarantee?

The energy crisis triggered a huge spike in demand for solar, and the number of solar panel installers in the UK has grown to a record high, totalling more than 3,300. If someone in the UK wants solar, they have a staggering amount of choice when it comes to picking an installer. 

However, despite the high number of businesses willing to put solar panels on people’s roofs, few of them offer any kind of maintenance, support or aftercare. This is a mismatch, given the high cost of a solar & battery system, and the importance of it lasting a long time. 

What’s more, 73% of solar PV installations in the UK now include a battery (according to Flexi-Orb), which typically stops working effectively during the system’s expected lifetime. And as with solar panels, there is a severe lack of businesses out there who will help homeowners with a malfunctioning battery.

In fact, industry technical experts generally estimate that a solar & battery system in the UK has a 15% chance of requiring maintenance every year across a 20-year period, with three call-outs needed on average. This adds not only cost, but also the hassle of finding a reliable installer to help each time.

It’s also a case of reassurance and peace of mind. A 2021 study by the Department for Business, Energy and Industrial Strategy (BEIS), found that 55% of people in the UK who don’t want (or aren’t sure about) solar panels reported maintenance concerns as a key reason, and 40% said that a guarantee scheme would allay these concerns. 

A solar system is a big investment, so it’s fair to expect it to work. So we created the Sunsave Guarantee to give UK households certainty they will get the best out of their solar system for at least 20 years.

What is the Sunsave Guarantee?

The Sunsave Guarantee ensures that your solar & battery system will remain in superb condition throughout the 20-year subscription term of Sunsave Plus. This means that once installed, you can rest assured that you’ll have a consistent supply of clean, green electricity.

All of our installations are performed to the highest standards using best-in-class kit, but the Sunsave Guarantee is there as a backup for total peace of mind. If anything stops working or drops below an acceptable level of performance, we’ll be there to fix it. 

Part of your fixed monthly fee for Sunsave Plus pays for the Sunsave Guarantee.

What’s included?

The Sunsave Guarantee includes:

  • 30-year performance warranty on the solar panels
  • A free battery replacement once it performs at less than 70% of its original capacity – which typically happens after 10-12 years
  • A free inverter replacement whenever required (usually after 10-12 years)
  • 24/7 monitoring of the solar & battery system, including alerting you if something isn’t working
  • Troubleshooting of any issues
  • Management of any warranty claims
  • Insurance provided by Aviva to protect your system against damage, fire, and theft
  • Downtime protection - we’ll compensate you for any prolonged period that your system isn’t working as it should

There are three key parts to the Sunsave Guarantee: monitoring, maintenance & replacement parts, and insurance & downtime protection. Here’s a bit more detail on each of them:


It’s important to keep an eye on your system to ensure that it’s always working properly. However, sometimes you might be too busy to do this, and it can be tricky to know the signs of an underperforming system unless you are an expert. 

That’s why we keep track of your panels & battery for you 24/7 using our remote monitoring platform. This means we’ll be able to spot any issues, let you know, and take the necessary actions to fix them. If you’re interested, you’ll also be able to see how much clean energy your panels are generating - and how much you’re saving. 

If something doesn’t look right (whether that’s been caught by us or raised by you) then we may need a bit of extra information, such as photos and documents. 

If we’re not able to fix it remotely, a Sunsave engineer will visit your property within two weeks (and often much sooner).

Maintenance & replacement parts

The Sunsave Guarantee is a promise that your system will keep working properly throughout the 20-year subscription period, which means that if something goes wrong, we’ll sort it - whether that means fixing the system, or completely replacing a part of it. 

The process is a bit different depending on whether the underperforming part of your system is still within warranty. 

If your panels, battery or inverter stop working before the end of their warranty, we’ll take care of submitting any claims to the manufacturer, and we’ll install any replacement hardware needed. 

Once your battery is out of warranty (normally after 10 or 12 years), if it’s performing at less than 70% of its original capacity, we’ll replace it with a brand new battery for free. Likewise, if your inverter is out of warranty and needs to be replaced, we’ll replace it with a new one for free.

After installation, if your system isn’t working and we need to send an engineer, there’s a call-out fee of £100, up to a maximum of £200 each year, plus VAT. That means even if you need multiple call-outs in one year, your costs will be capped.

Insurance & downtime protection

Your Sunsave Plus system comes with insurance provided by Aviva, and is insured against damage from theft, vandalism, natural catastrophe and fire. For instance, if a storm blew your panels off the roof, you’d be fully covered.

Alongside the insurance, we also provide downtime cover - so if your system is not working correctly, we’ll credit your monthly payments while we work to get it back to full health.

Who can get the Sunsave Guarantee?

Every Sunsave Plus subscription is covered by the Sunsave Guarantee, which lasts for the full subscription term of 20 years.

You can fully repay your loan early and without any penalties or fees, but doing so will mean you’re no longer protected by the Sunsave Guarantee.

Black solar panel array on a brown rooftop in a UK neighbourhood, other houses in the background

How often does a solar & battery system need maintenance?

As mentioned previously, industry technical experts generally estimate that a solar & battery system in the UK has a 15% chance of requiring maintenance every year across a 20-year period. 

This means on average your system will require three maintenance call-outs across its first two decades: one for your solar panels, one for a defunct battery, and one for a defunct inverter. 

Here’s a bit more detail about each of the three components.

Solar panel maintenance

Solar panels are sturdy objects with no moving parts, which means in an ideal world you can have them installed and never think about them again (known as ‘fit and forget’). 

However, this doesn’t mean there are never any problems. 

In a survey of solar panel owners conducted by Which? in October 2022, people reported the following issues with their systems: electrical problems, generation meters breaking, panels producing less electricity, panels producing no electricity, weak electrical connections, cracked/broken glass on panels, and isolator problems. 

Some of the things that can cause a solar panel system to malfunction include:

  • Improper installation - dodgy connections will lead to problems further down the line 
  • Low quality hardware - if the kit isn’t up to scratch, it can deteriorate pretty quickly
  • Birds - they can nest under solar panels and damage wiring
  • Falling branches and other debris - this can cause small cracks in the glass that eventually lead to mechanical failures 
  • Sea air - the salt blown onto solar panels by the sea can slowly degrade the hardware
  • Shading - when parts of solar panels are shaded for a long period of time, it can create ‘hot spots’ which reduce output

With Sunsave’s top-quality kit and professional installation, solar panel issues are unlikely, but sometimes things do go wrong - and the Sunsave Guarantee is there for total peace of mind.

Battery maintenance

Solar batteries are significantly less sturdy than solar panels, and consequently have a much shorter lifespan. 

Whenever you charge and then discharge a solar battery, this is referred to as a ‘cycle’, and a battery can only take so many cycles. That’s why most solar battery warranties are expressed in two different ways: cycles, and years. 

Batteries help you save money and are there to be used, so there’s no point avoiding the cycles. You just need to take other sensible measures to ensure your battery performs well for as long as possible, such as keeping the area around it ventilated and cool. 

Most solar batteries tend to last somewhere between 10 and 12 years, which means you’ll almost certainly need a new battery during the lifespan of your system. Once your battery is no longer performing as it should, this will be automatically flagged by our monitoring platform and we’ll provide a free replacement.

Inverter maintenance

In the same survey conducted by Which? in October 2022, the most common issue reported by solar panel owners was a malfunctioning inverter, with greater than 10% reporting this as an issue. 

Similarly, a study from the Bern University of Applied Sciences published in 2023 shows that more than one third of inverters fail in their first 15 years. 

Any solar system depends completely on the health of the inverter, as this is the machine that ensures all the electricity is actually usable (and can be exported to the grid). 

Solar inverters come with a 10-year or 12-year warranty, and by year 14 it becomes significantly more likely that the inverter will fail - as shown by the chart below.

However, if your inverter is not working and is preventing your solar panels from achieving at least 80% of their original output capacity, we’ll install a new one for free.

What’s not included? 

The Sunsave Guarantee does not include replacement bird protection or solar panel cleaning services.

If you opt to have bird protection added to your Sunsave Plus system at the point of install, this should comfortably last the system lifetime. And any damage that birds might cause to your solar panels is covered by the insurance policy. 

In the case of solar panel cleaning, it is rarely required because solar panels are ‘self-cleaning’ - particularly in the UK. 

That’s because they’re treated with a special hydrophobic coating, which means water droplets just roll straight off them. Once solar panels are installed at an angle, any rainfall just runs down the solar panels and cleans them in the process. 

On the rare occasion they do need cleaning (perhaps if you live in a very dry, dusty area), you can do this from ground level with an extendable brush. Alternatively, it shouldn’t cost more than around £100 to have someone come over and clean your solar panel system and many window cleaners offer this service. 

If your solar panels are on your roof you should be careful about doing the cleaning yourself. Unless you have an extendable, soft brush that you can use whilst standing on the ground, it is recommended that you get a professional to clean your solar panels.

Do other solar installers offer monitoring and maintenance?

It is unfortunately very uncommon for solar installers to offer monitoring and maintenance support in the UK, with only a two-year workmanship guarantee as standard.

A common attitude in the industry is to focus on selling to new people, but not to support existing customers. For many people with solar, if something goes wrong they will often struggle to find an installer who is willing to help them (unless they pay a huge fee).

With the Sunsave Guarantee we’re aiming to establish a new standard of care in the UK solar industry.

Next steps

Having a solar system should be an stress-free experience, and that’s exactly what the Sunsave Guarantee has been designed to provide. With Sunsave Plus, you can switch to solar and enjoy a reliable source of clean, green electricity for the next 20 years. 

If you’re interested in Sunsave Plus, check out this page for more information, or sign up now.

Copyright © 2024 Sunsave

Sunsave Group Limited (company number: 13741813) and its affiliates, Sunsave UK Limited (company number: 13941186) and Sunsave Energy Limited (company number: 13952135), together trading as “Sunsave”, provide renewable energy systems and finance and are registered at 23 Ansdell Terrace, London, W8 5BY. Sunsave Energy Limited (FRN: 979494) is a lender authorised and regulated by the Financial Conduct Authority. Sunsave UK Limited (FRN: 977566) acts as a credit broker and can introduce you to a panel of lenders for the purpose of arranging finance. Sunsave UK Limited is an appointed representative of Product Partnerships Limited (FRN: 626349) which is authorised and regulated by the Financial Conduct Authority and registered at Suite D2 Josephs Well, Hanover Walk, Leeds, LS3 1AB.