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Best solar panel brands: reviewed and tested by experts
With over 10 years’ experience writing about consumer affairs, Sarah leads on energy content at Which?, helping customers navigate the market and exposing poor practice.
A veteran consumer advocate with over two decades of rigorous product-testing experience, Lisa leads our mattress category and joined the home energy team, helping bring clear, actionable advice to consumers.
In this article
- How do you buy solar panels?
- Which? member exclusive offer: solar installation
- Does the brand of solar panel matter?
- The most popular solar panel brands: lab test results and reviews by owners
- How solar panel scores are calculated
- What makes a Which? Recommended Brand for solar panels
- Next steps towards buying new solar panels
Solar panels are a long-term investment as they'll be on your roof for 20 years or more.
So choosing the right solar PV (photovoltaic) system for your home is important, as well as hiring an installer you feel confident in.
To help you make your choice of solar panel brand, we’ve tested a selection of panels from some of the most popular brands in the UK, including Aiko, JA Solar, Longi and Trina Solar.
We also surveyed Which? members who already own solar panels, so we can reveal the most popular brands and tell you what real owners think of them**.
You can also see our guides on how much solar panels will cost for your home and find out more about solar panel installation.
Which? members can log in to see our lab test results and find out what owners of each brand think. If you're not a member, join Which? to get access to the results and our independent research.
How do you buy solar panels?
In the UK, generally, you’ll buy solar panels through an installer. It's unusual to choose a specific solar panel brand at the outset. Instead, the installer will suggest a brand as part of your quote. A lot of installers only work with one brand of panel, although some installers work with two different brands. Very few install more than two brands. So it’s vital to get a few different quotes and compare what you’re being offered.
Once you’ve made your decision, your chosen installer will typically buy the panels to fit on your home, so you won’t deal with the brand directly. When you’re getting quotes from installers, make sure you ask about what guarantees are in place, both for the panels themselves and for the installation job.
With energy prices rising in 2026, solar panel installers have reported a boom in enquiries about solar panel installations. Product availability in the UK is increasing, so this can also determine which brands installers are able to fit.
We'd recommend getting three different installation quotes to compare.
When you talk to installers, use our research on solar panel brands to help you choose between them.
Read more: buying advice for solar panels
Which? member exclusive offer: solar installation
This year, Which? members can choose from a variety of solar panel discounts and offers from Which? Trusted Trader installers.
Explore our selection of solar panel offers before choosing the one that works best for you and the region you are in.
The offers will be available until 30 September 2026, and terms and conditions apply.
Head to our solar panel Which? member exclusive page to find out more.
Whether you are a Which? member or not, you can also use our home energy planning service to get a personalised energy plan for your home, or learn more about using a vetted installer through Which? Trusted Traders.
Does the brand of solar panel matter?
As with many home improvement projects, the most important part of a solar panel installation is to find an installer who you can trust to do a good set-up job.
However, when you are comparing your options, it's worth knowing that solar panel brands' products can vary in terms of their:
- product range
- maximum power output
- efficiency
- warranties (for the product and power output)
- what owners think of them.
Brands also differ in overall panel performance. We lab test panels from some of the most popular brands to see how efficient they are at converting solar to energy you can use at home, and we’ve found that there are differences between the panels we’ve tested.
We've outlined the product warranties and power output warranties from some of the most popular brands below. The quality of the installation and other equipment (such as the inverter) will also contribute to how good the solar panel system is overall. Price also varies depending on the solar panel brand and installer.
The most popular solar panel brands: lab test results and reviews by owners
The Which? members we surveyed owned solar PV panels from more than 20 different brands*.
To help you narrow down the choice from your installer, or check how a suggested brand compares, we've tested a selection of panels from popular brands.
Our lab tests show whether a brand's solar panels:
- can do what they claim
- are efficient at converting solar into power
- degrade overtime
- come with any micro damage that cannot be seen by eye.
We've combined these test results with our existing survey results** of more than 2,000 people with solar panels on their homes.
Their feedback gives you unique insight into:
- why owners chose the brand
- what owners like most about their solar panels
- gripes and frustrations owners have with their solar panels
- owners' assessment of their solar panels' electricity production and appearance
- what owners think of the manufacturer's customer service (if they've needed to use it).
The table below shows how some of the most popular solar panel brands compare on warranties and maximum power output and efficiency.
Click on the brand names below to go straight through to the review page where you'll find details of the panels we've tested and owners comments we've gathered.
Which? members can log in to see how the brands compare in the section below.
If you're not a member, join Which? to get access to the results. You'll also be able to access our exclusive offers from a variety of solar panel installers.
The brands included are some of the most commonly owned, by those who bought and installed solar panels within in the last three years*
Specification information is based on the most efficient domestic monofacial (one-sided) solar panel available online for each brand, in July 2026, or information taken from our latest test data.
| Solar panel brand | Number of panels tested | Product warranty | Power output warranty | Maximum power output and efficiency |
|---|---|---|---|---|
| Aiko | 3 | 12 years | 85.85% at 30 years | 640W at 23.7% |
| Canadian Solar | 0 | 12 years | 84.8% at 25 years | 590W at 21.3% |
| JA Solar | 4 | 12 years | 87.4% at 25 years | 600W at 23.2% |
| Jinko Solar | 0 | 30 years | 87.4% at 30 years | 460W at 22.4% |
| Longi | 3 | 20 years | 88.9% at 25 years | 575W at 22% |
| REC solar | 2 | 25 years | 92% at 25 years | 460W at 22.1% |
| SolarEdge | 0 | 25 years | 84.8% at 25 years | 370W at 20.3% |
| Trina Solar | 2 | 25 years | 89.4% at 25 years | 450W at 22.5% |
The brands included are some of the most commonly owned, by those who bought and installed solar panels within in the last three years*
Specification information is based on the most efficient domestic monofacial (one-sided) solar panel available online for each brand, in July 2026, or information taken from our latest test data.
How solar panel scores are calculated
In 2026, we started testing solar panels with other European consumer research organisations. A Which? solar panel test score is made up of results from dozens of individual tests and checks. Test scores are calculated as follows:
- 37.5% - Determination of maximum power
This includes the highest power the PV panel produces in standard test conditions, how efficient the panel is at processing solar and turning that into power. We compared the power when the panels are new and work out how much the panel degrades over our tests and compare that to the information given on the nameplate. - 37.5% - Energy production
Based on simulations run for Belfast, Cardiff, Edinburgh, London and Manchester - 25% - Defects
Special images are taken to detect minute defects and cracks created during the initial test programme, and we run tests to check for current leakage in wet conditions.
Find out more in our detailed guide to how we test solar panels.
What makes a Which? Recommended Brand for solar panels
As this is the first time we're testing solar panels, our current Which? Recommended Brands for solar panels are based purely on our testing results.
To become a Which? Recommended Brand for solar panels, the brand's panels need to perform well in our tests, meet safety requirements and provide a satisfactory warranty:
- The average total test score of all panels tested from the brand must be higher that the overall average score of all panels we've tested.
- All panels must score 5*s for efficiency
- All panels must score 4* or higher for power
- All panels must score 4* or higher for defects
- All panels must pass safety tests
- Offer a minimum 12 year product warranty
- Offer a minimum 25 years power output warranty
We also check that any eligible brands are listed as a Tier 1 PV model supplier. This is something that Bloomberg allocates to PV solar panel manufacturers as an indication of the financial stability of the company.
Our assessment and methodology for awarding solar panels WRBs is liable to change and evolve as we test more panels over the next 12 months. We'll update our how we test information accordingly.
Next steps towards buying new solar panels
Remember that choosing a decent installer is a crucial step when buying solar panels. Head to our guide on how to choose a solar installer, or search for a Which? Trusted Trader near you.
As well as deciding on your installer and the brand of solar panels, you can use our advice to:
- Find out how much solar panels cost for different system sizes and outputs.
- Gauge if solar panels are worth it for your home.
- Weigh up the benefits and costs of pairing your panels with solar panel battery storage.
- Check if your home is suitable and know what to expect from a solar panel installation.
*In January 2026, we surveyed almost 900 solar panel owners via an online survey to see which brands they owned.
**In April 2024, we surveyed more than 2,000 Which? members who have solar panels on their home to find out their thoughts about brands.
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