TL;DR
Choosing the best solar panels is one of the most important decisions you will make when installing solar. The panel you choose directly affects how much electricity your system generates, how long it lasts, and how quickly it pays for itself. In short, it has a material impact on the lifetime return from your roof.
In this guide, we compare the best solar panels UK homeowners can install in 2026, explaining why the highest wattage panel is not always the best choice. We break down the key differences in efficiency, shade performance, temperature behaviour, bifacial capability, warranties and real world value, and show how different panels suit different roof types and installation scenarios.
How to Choose the Best Solar Panel?
There is no single best solar panel for everyone. The best solar panels UK homeowners can install depend on roof size, roof type, shading, orientation, temperature and even aesthetics. A panel that performs brilliantly on a large, open pitched roof may not be the right choice for a shaded roof, a flat roof, or an in roof system.
Solar technology also moves quickly. At the start of 2025, we reviewed the leading panels on the market, but several manufacturers have since released new flagship models. This article updates that analysis and looks at the best solar panels available in 2026, comparing them across five core technical metrics that genuinely matter.
If you are researching the best solar panels UK homeowners can buy, or comparing the best solar panels companies UK installers are offering, this guide is designed to give you a clear, technical foundation to make the right choice. And, of course, do check out our video on the topic as well.
We are comparing six panels from five manufacturers that represent the current top end of the residential market in 2026.
AIKO was founded in 2009 and is headquartered in Shenzhen. Over the past two years it has become one of the most talked about manufacturers in the industry due to its rapid progress in high efficiency cell technology.
We are looking at both the NeoStar 3S all black panel and the NeoStar 3P, which is not fully black but offers slightly higher efficiency.
Eurener is a Spanish manufacturer based in Valencia and established in 1997. The company focuses on high quality modules with an emphasis on ethical manufacturing and long warranties. The Nexa 500 W is its flagship residential panel.
LONGi was founded in 2000 and is currently the largest solar manufacturer in the world by volume. Historically known for high volume, lower cost modules, the S10 is LONGi’s deliberate attempt to produce the best solar panel on the market rather than the cheapest.
REC was founded in Norway in 1996, with manufacturing based in Singapore. REC panels have a strong reputation for build quality, low degradation, and robust warranties, with less reliance on Chinese manufacturing than many competitors.
JA Solar was founded in 2005 and is one of the most widely used Tier One manufacturers globally. While this panel is lower power than the others in this comparison, it is currently offered by Octopus Energy, which makes it relevant for many UK homeowners.
Module efficiency tells you how much electrical power a panel can produce per square metre. It is measured by shining 1,000 watts of light per square metre onto the panel and measuring the electrical output. A panel producing 250 watts per square metre has a module efficiency of 25%.
Efficiency matters because roof space is limited. Higher efficiency panels generate more power from the same area, improving the return from your roof.
The highest efficiency standard sized panel in this comparison is the AIKO NeoStar 3P. The 485 W version achieves 24.3% efficiency, while the top 500 W variant reaches 25%, which is a major milestone for silicon based solar panels.
The all black AIKO NeoStar 3S 480 W follows closely at 24%. The LONGi S10 495 W panel is rated at 24.3%, although part of this comes from the panel being slightly larger. On a like for like basis, the underlying cell technology in the AIKO remains marginally ahead.
Eurener’s Nexa 500 W panel sits at around 23.1% on the front side. The REC Alpha Pure RX is rated at 22.6%, with the JA Solar 450 W panel at approximately 22.5%.
The reason AIKO and LONGi lead here is their use of all back contact cell technology. By moving all electrical contacts to the rear of the cell, more of the front surface is dedicated to electricity generation. This improves efficiency and also creates a very clean, uniform black appearance on the roof.
Shading is one of the biggest real world challenges for UK solar installations. Chimneys, dormers, trees and neighbouring buildings all cast moving shadows that can significantly reduce output if not handled correctly.
Traditional solar panels are divided into three electrical zones protected by bypass diodes. When part of a panel is shaded, the diode activates and that entire third of the panel effectively switches off. Good system design involves orientating panels so that shade crosses the panel in the least damaging way.
New all back contact technology has improved this behaviour. Panels like the AIKO NeoStar range and the LONGi S10 allow current to flow through smaller groups of cells even when partially shaded. This does not make the panel immune to shade, but it does significantly reduce the losses caused by partial shading.
REC sits between the two groups by using four bypass diodes instead of the usual three. This limits shading losses to a smaller section of the panel than a conventional layout.
Eurener and JA Solar use a standard three diode configuration. They perform as expected for traditional modules but do not offer the enhanced shading tolerance of AIKO, LONGi or REC.
For roofs with moving shade, the AIKO NeoStar range and the LONGi S10 are likely to be the strongest performers, with REC close behind.
Bifacial panels can generate electricity from both the front and the rear. Eurener, REC and JA Solar all offer bifacial capability.
On a typical pitched tiled roof, the rear of the panel sits close to the roof surface and receives very little reflected light. In these cases, the bifacial gain is usually negligible.
On flat roofs and ground mounted systems, the situation is different. Panels are raised and tilted, allowing light to reflect onto the rear of the panels from the surface below or from adjacent rows. In these scenarios, bifacial panels can deliver a meaningful increase in output and are well worth considering.
If you are installing on a flat roof or ground mount, your installer should be able to model the rear side contribution accurately.
As solar panels heat up, their efficiency drops. The temperature coefficient tells you how much power is lost for every degree Celsius above the standard 25 degree test condition.
In the UK, cell temperatures can still reach 60 to 70 degrees on sunny days, particularly on dark roofs or in roof systems with limited airflow.
The LONGi S10 and REC Alpha Pure RX lead here with a temperature coefficient of around minus 0.24 percent per degree Celsius. The AIKO NeoStar panels follow closely at around minus 0.26 percent. Eurener sits at around minus 0.29 percent, with JA Solar closer to minus 0.3 percent.
In practical terms, a 500 W panel with a minus 0.24 percent coefficient will produce roughly 445 W at 70 degrees cell temperature, compared to around 433 W for a panel at minus 0.3 percent.
Solar panel warranties consist of a product warranty and a performance warranty.
AIKO offers a 25 year product warranty and a 30 year performance warranty, guaranteeing 88.85% of original output at year 30.
LONGi matches the 30 year performance warranty and offers a 30 year product warranty on the S10.
Eurener also offers 30 year product and performance warranties, guaranteeing 88% retained output, although the full product warranty applies only when supplied by a Eurener Premium Partner.
REC offers a 25 year product warranty and a performance warranty guaranteeing 92% output at year 25, which is shorter but tighter.
JA Solar typically offers a 25 year product warranty and a 30 year performance warranty.
Long term modelling should always account for panel degradation. The best solar panels companies UK installers work with should be transparent about this in their yield forecasts.
Panel prices are usually discussed in pence per watt. The JA Solar 450 W panel is the cheapest at around 11p per watt. Eurener sits at roughly 15p, LONGi around 17.5p, AIKO around 18.5p, and REC significantly higher at around 31p per watt.
In the context of a full solar installation, these differences are relatively small. Labour, scaffolding, inverters and batteries make up the bulk of system cost. The panel is the component that actually generates the return, so choosing the right panel for your roof is far more important than saving a small amount on unit cost.
Looking purely at the data, AIKO leads on efficiency, with LONGi close behind. For shade mitigation, AIKO and LONGi are the strongest performers, with REC in the middle due to its four diode design. For bifacial installations, Eurener, REC and JA Solar are relevant options. On temperature performance, LONGi and REC come out top, with AIKO very close behind. Warranty coverage is strongest from AIKO, LONGi and Eurener.
In most real world UK installations, the decision often comes down to AIKO or LONGi, depending on roof constraints, shading and system design.
If you are looking to install solar or battery storage and want a system designed around your roof rather than a one size fits all approach, Spirit Energy provides fully bespoke technical designs focused on long term performance and return.