LONGi solar panels: Hi-MO X10, EcoLife and the warranty on your code

LONGi is worth comparing if your roof is short of space or you care how the panels look: its Hi-MO X10 and EcoLife ranges use back-contact cells, which fit more watts into a house-size panel and give a plain black front. LONGi's warranty depends on the code. Its EcoLife warranty (December 2025) gives 30 years' product cover to the LR7-54HVB, HVBB, HJD and HJBB house panels, while its Hi-MO X10 warranty (April 2026) gives 15 years to the HVH and HVD codes, although the Hi-MO X10 page advertises 30. Ask for the document that names the code on your quote. LONGi sells in the UK through six UK distributors on its official partner list, and its panels are in the MCS product directory.

How back-contact panels help on a small roof

In most solar cells, thin metal lines on the front collect the current. In a back-contact cell those connections sit behind the cell, so more of the front surface catches light. LONGi calls the version in its Hi-MO X10 panels HPBC 2.0. The practical result is more power per square metre and a cleaner look.

That matters when the roof, not the budget, limits the system. Example (illustrative): fourteen 450 W panels make 6.30 kWp, while twelve 500 W panels make 6.00 kWp. The more powerful panel only wins if it fits where the smaller count doesn't, so compare layouts, not wattages. Our guide to how many solar panels you need starts from the usable roof area.

LONGi also publishes TÜV Rheinland and CPVT shading tests in which its Hi-MO X10 panels lost less power under partial shade than the TOPCon panels tested. A small, moving shadow may cost less; a tree or chimney that covers panels for hours still costs output. Ask for a shade assessment of your own roof; our solar panel shading guide explains what to look for.

Which LONGi panels you'll see on UK quotes

LONGi's European site sells house panels under the EcoLife name, alongside its Hi-MO X10 commercial range. A good quote gives the full model code, so it helps to be able to read it:

One house panel you may be quoted is the LR7-54HVBB, a black dual-glass panel that LONGi sells as part of its EcoLife range. LONGi's datasheet page we checked for the 470–485 W version gives 1,800 × 1,134 × 30 mm, 23.5 kg, efficiency of 23.0% to 23.8% and a temperature coefficient of −0.26% per °C, the share of output lost per degree the cells run above 25 °C. It is 38 mm longer than the 1,762 mm length many 54-cell panels use, which can matter on a tight roof; our guide to solar panel sizes covers the dimensions.

The same page also rates the panel with 5% to 25% extra output from the back; the 470 W version becomes 588 W at 25%. On a pitched roof with the panel close to the tiles, little light reaches the back, so ask for your production estimate at the front-side rating.

What the LONGi warranty actually says

A solar panel has two warranties. The product warranty covers defects in materials and manufacture. The power warranty promises a minimum output over time, measured under test conditions; it doesn't guarantee your yearly generation.

LONGi's Hi-MO X10 and EcoLife pages both advertise a 30-year product warranty and a 30-year power warranty. Behind them sit two separate warranty documents for rooftop ("distributed generation") systems, and they cover different codes:

The LR7-54HVBB isn't in the Hi-MO X10 table: it is covered by LONGi's separate EcoLife warranty document (edition 2025.12), which gives the HVB, HVBB, HJD and HJBB codes a 30-year product warranty and the same 30-year power warranty. So "30 years" is right for an EcoLife code and wrong for a Hi-MO X10 code such as LR7-54HVH; ask for the document that names yours. In both documents the power warranty covers front-side output only.

The power warranty is easy to check with the formula both documents use: after 30 years a 480 W panel should still produce at least 426 W under test conditions (480 × (1 − (1% + 0.35% × 29)) = 480 × 0.8885 = 426.5 W). The EcoLife document states its year-30 figure as 88.9%.

Both documents set the same conditions that matter at home:

• The warranty belongs to the buyer in LONGi's sales contract, usually your installer or their wholesaler, or someone LONGi confirms in writing as their successor.
• Claims must reach LONGi or its authorised distributor in writing within 30 days of spotting the problem, with the serial numbers, proof of purchase and project location.
• Removal, repacking and reinstallation are at the customer's cost, and a repaired or replacement panel keeps the original warranty period.
• Panels moved outside the sales region lose cover unless LONGi agreed first, which is another reason to buy through a UK channel.

Our guide to how long solar panels last explains how a power warranty relates to real ageing.

Buying LONGi panels in the UK

LONGi's official partner list for Europe names six UK distributors: CCL Components, City Plumbing Services, Midsummer, Segen, Solen Energy and UK Greentech. Its panels are in the MCS product directory under LONGi Green Energy Technology Co., Ltd.; the LR7-54HVBB is listed from 460 W to 495 W on a certificate running from 28 January 2026. Look up the code on your quote there.

In Great Britain, electricity suppliers pay for the power you export through their own Smart Export Guarantee tariffs, on rates and terms each supplier sets, and they need your installation to hold an MCS certificate (or an equivalent certification). Northern Ireland has no SEG.

A LONGi system that one installer supplies and fits at your home carries no VAT through 31 March 2027, and 5% VAT from April 2027 onwards unless the government extends the relief. Buy the panels on their own and you pay 20%.

Because LONGi's warranty is written for the trade buyer, the business that sold and fitted your panels is the one you deal with first. Its obligations to you come from the Consumer Rights Act 2015 rather than from LONGi's paperwork: faulty goods, or work not done with reasonable care and skill, are its problem to put right. Ask the installer to confirm in writing that it will handle a LONGi claim for you, including roof access, for as long as it guarantees its workmanship. If it says it is a RECC or HIES member, check the code's register; MCS no longer requires membership.

Before you accept a LONGi quote

• The full code (for example LR7-54HVBB-480M), the number of panels and the total kWp.
• The datasheet and the LONGi warranty document that lists that code, with the product-warranty years stated on the quote.
• A roof layout and a production estimate at the front-side rating.
• Which UK distributor supplies the panels, and the serial numbers at handover.
• A written promise on who raises a warranty claim and pays for access and refitting.

Our guide to comparing solar quotes covers the rest of the paperwork.

Is LONGi right for your roof?

LONGi is a strong candidate when the extra power per square metre changes what fits on your roof, or when you want an all-black look. On a large, clear roof, a lower-cost panel may reach the same kWp; the decision then comes down to price and the warranty document each installer can show you.

For another back-contact brand, compare AIKO. For TOPCon panels, compare JA Solar and JinkoSolar. Our best solar panels guide sets out how to compare them on the same roof.

LONGi solar panel FAQs

Are LONGi solar panels any good?

LONGi's house panels use back-contact cells with high efficiency figures: 23.0% to 23.8% on the LR7-54HVBB datasheet page we checked. They suit small or visible roofs. Judge a quote on the layout, the installed price and the warranty document for the exact code.

Does LONGi give a 30-year product warranty?

On its EcoLife house panels (LR7-54HVB, HVBB, HJD, HJBB), yes: the December 2025 EcoLife warranty gives 30 years. The April 2026 Hi-MO X10 warranty gives 15 years to HVH and HVD codes. Ask for the document that names your panel's code.

Do back-contact panels stop shading losses?

No. They may lose less under a small shadow, but blocked light is still lost. Place panels away from chimneys and trees, and ask for a shade assessment.

Where can I buy LONGi panels in the UK?

Through an MCS-certified installer, who buys from a UK distributor. LONGi's partner list names CCL Components, City Plumbing Services, Midsummer, Segen, Solen Energy and UK Greentech.