Best solar panels UK: efficiency, warranty and price compared

Which solar panels should you shortlist?

For limited roof space, compare AIKO Neostar 3S+ 480 W against the actual roof layouts: it leads on front-rated watts per panel area here. JA Solar's 450 W panel is a lower-output option in the same footprint. LONGi's 485 W Hi-MO X10 may suit a layout that accommodates its larger module. These choices come from three documented models.

STC uses a cell temperature of 25°C and sunlight of 1,000 W/m². A panel's watt rating is a laboratory output, not the power it produces all day. The chart compares output per panel area, which is more useful for a tight roof than watts per panel. [1] [2]

How did we compare the panels?

This is a desk comparison of manufacturer documents and dated UK seller listings. We have not installed or tested these panels. We compare exact model codes, front-rated output, dimensions, efficiency, warranty terms and price evidence. There is no numerical score or single winner.

The shortlist is deliberately bounded: three models with readable specifications, documented warranty terms and issued certification evidence. It is not every panel sold in the UK. Our choices do not rank real-world reliability, customer service, annual generation or financial strength; we have no comparable first-hand evidence for those.

Original issued MCS 005 certificates cover the model ranges that include these three panels. We read in-date certificate copies from the certification bodies, hosted by distributors; these are documentary checks, rather than successful live-directory searches. Have your installer confirm the active exact-model listing and the warranty supplied with your quote. [7] [8] [9]

For roof space, the decision rule is watts divided by full panel area. For warranty, product cover is compared separately from performance cover. For price, the model and VAT basis must match, and delivery is checked separately.

Which is best when roof space is limited?

LONGi's 485 W model produces more watts per panel, but it is longer: 1800 mm against 1762 mm. It works out at about 237.6 W/m², compared with AIKO's 240.2 W/m². [3] [1]

The layout can change the choice. Ten LONGi panels give 4.85 kWp against ten AIKO panels' 4.80 kWp. If only nine LONGi fit, they give 4.365 kWp. These are our rated-capacity calculations, not surveyed layouts or annual generation forecasts.

Ask for two layouts with the same roof setbacks and obstacles. Compare total kWp, predicted annual kWh and the extra installed price. See how many solar panels you need for the sizing task.

When is the JA Solar 450 W panel worth comparing?

Compare it when panel price matters more than the last 30 W per panel. In the same footprint as the AIKO 480 W, JA's JAM54D41-450/LB is rated 450 W at 22.5 per cent efficiency, and on 13 October 2026 its retail listing was £36.29 cheaper per panel than the AIKO listing at the same seller (both including VAT, panels only). [2] [6] [11] It uses dual glass and is bifacial. Its stated weight is 22 kg, compared with AIKO's 24.2 kg. Ask the installer to assess the complete array load, mounting and roof, rather than selecting on panel mass alone. [2] [1]

Our row is the version with 25-year product cover and 30-year performance cover. That term appears in both the 25-year datasheet on JA's European website and the exact model-family row of JA's issued February 2026 policy. The applicable sale-date policy still belongs with your quote, especially when older stock or another warranty version is offered. [2] [10]

Bifacial means the rear can also generate. It does not tell you how much extra electricity a close-mounted pitched-roof installation produces. Request the mounting arrangement and rear-light assumption before accepting a forecast uplift. Our comparison uses front-only STC ratings for all three panels.

What does a 30-year solar panel warranty cover?

Product cover concerns defects. Performance cover sets a minimum remaining panel output under specified conditions. A long performance warranty does not promise the same annual household savings, or cover every cost of getting a replacement onto the roof.

AIKO states 30 years of product cover and 30 years of performance cover for this model. Its performance floor is 88.85 per cent at year 30; LONGi's year-30 floor is also 88.85 per cent and JA's is 87.4 per cent, and all three apply to front-side output only. AIKO's cover is restricted to products sourced through official local channels, and removal, repackaging and installation or reinstallation expenses fall to the customer. AIKO's 30-year product term is the longest stated here, rather than proof of better reliability. [4] [5] [10]

JA's issued policy supports the 25-year product term for JAM54D41/LB. Which JA policy applies depends on when JA first sold the module. Under the February 2026 policy, cover starts at delivery or six months after the panel left the factory, whichever is earlier, not the day it is fitted. AIKO's and LONGi's warranties also start from delivery or a set time after factory dispatch. JA's policy also leaves removal and reinstallation expenses to the customer. [10] [4] [5]

LONGi's LR7-54HVH has 15 years of product cover and 30 years of performance cover. Its April 2026 warranty puts dismantling, repacking and installation or reinstallation costs on the customer. Ask who pays labour, transport and roof access on the complete installation contract. [5]

Keep the invoice, serial numbers and exact applicable warranty. Each maker's warranty is given to the buyer named in its sales contract, which may be your installer's supplier rather than you. Ask the installer to transfer or register the warranty to you in writing, and who handles a claim if they stop trading. [5] [4] [10]

How much do these solar panels cost?

Two matched retail listings show the price of the panels alone. They exclude installation and roof equipment, and show no delivery charge. They cannot establish which full installation is best value.

The JA listing is cheaper per panel and per rated watt (18.2p against 24.6p per watt, equipment only, both including VAT), but it buys 30 W less per panel. Freight, order size, installer buying prices and the proposed layout can change the overall comparison. Treat those shop prices as evidence of hardware cost, not a price you should expect to pay for a fitted system.

For an installer quote, compare the whole price with and without the panel upgrade. A hypothetical £300 premium for 0.3 kWp extra capacity costs £1,000 per additional kWp. That calculation measures the premium, not payback: whether it earns its cost depends on extra annual output and how much you use or export.

Use UK installed solar panel costs to judge the complete system. Installation includes much more than the modules.

Are the most efficient solar panels always the best?

Higher efficiency gives more rated output from the same panel area. It can be valuable on a small roof. If both options already meet your needs within the available space, a premium buys extra output whose value depends on how much of it you use at home rather than export.

Ask for predicted annual generation with shading and roof direction included, plus the inverter specification and export limit. Do not select a brand solely from its highest advertised family efficiency: our AIKO row uses the exact 480 W column, not the 490 W family headline. [1]

A bifacial panel also needs a credible rear-light assumption. A laboratory rear-gain example is not a measured result for your roof.

None of the three makers publishes a shading test we can compare. All three datasheets list three bypass diodes, and AIKO's also claims partial shading optimisation, which is the maker's claim rather than a measured result. On a shaded roof, ask for a forecast that models the shade and whether optimisers or microinverters are proposed. [1] [2] [3]

What should you check before choosing?

Which brand of solar panels is best in the UK?

Start with the exact panel offered, its roof fit and the full quote. A brand can sell several families with different sizes, efficiencies and warranties. Our shortlist answers particular buying situations; it does not rank every product in a brand.

Should I replace working panels with more efficient ones?

Not on the efficiency number alone. Request a comparison of leaving them in place against replacement, including removal, new equipment and any lost tariff benefits. If the system receives Feed-in Tariff (FIT) payments, a Great Britain scheme, check the Feed-in Tariff guide before approving changes.

What are the best solar panels with battery storage?

Choose the battery and inverter around usable storage, charge and discharge power, tariff use and any backup requirement. A panel label alone cannot answer that. Our home battery comparison separates those choices.

Before accepting, get the full module code, roof layout, forecast assumptions, applicable warranty and complete installed price in writing. Then check the solar quote rather than choosing on the brand name.