If you’ve been quoted on LONGi panels, there’s a good chance you’re staring at the model names wondering what on earth the difference is. Hi-MO 6 versus X6. X10 versus S10. Then there’s the Hi-MO 7 and the Hi-MO 9, which sound like newer versions but aren’t really for homes at all. It’s genuinely confusing, and most installers don’t explain it well.
Here’s the good news: once you understand that LONGi’s range is really just a ladder of cell technologies, the whole thing falls into place. This page maps the entire LONGi range, rates each panel honestly, and tells you exactly which one belongs on your roof – whether you’re after the best value, the highest efficiency, or just the safe default that works for most UK homes.
We haven’t bench-tested these in a lab. What you’re getting is our read on the numbers, the warranties, and what installers report from real UK rooftops, distilled into clear “buy it if / skip it if” guidance.
- LONGi is the world’s largest solar manufacturer – Tier 1, AAA bankable, and the company behind your warranty isn’t going anywhere.
- The range is best understood as cell-tech generations, not random model numbers. Once you see the ladder, the names make sense.
- The Hi-MO X10 is the pick for most UK homes – it’s our editor’s choice and the sensible default.
- The Hi-MO S10 is the new efficiency leader, with a world-first cell design and a 30-year product warranty.
- The Hi-MO 7 and 9 are utility panels for solar farms and big commercial roofs – not your house.
- The Hi-MO 5 is legacy – a fine panel in its day, now only worth buying cheap or second-hand.
- Naming warning: “Hi-MO 6” and “X6” are the same panel at many sellers, and the Hi-MO 9 is newer than the Hi-MO 7 despite the lower number.
About LONGi
LONGi is the biggest solar panel manufacturer on the planet, producing somewhere around a quarter of the world’s modules. They’re vertically integrated, meaning they make everything from the raw silicon wafers up to the finished panel, which gives them tight control over quality. They hold Tier 1 and AAA bankability ratings, plus EcoVadis Gold and Solar Stewardship Initiative Gold accreditations.
Why does this matter to you? A 25 or 30-year warranty is only worth as much as the company standing behind it. LONGi is about as safe a bet as the solar industry offers, and they’re a genuine technology leader – they hold world records in both back-contact panels and next-generation perovskite cells.
Two honest notes. First, LONGi has been loss-making during a sector-wide price downturn, though it remains cash-positive and dominant, so this is an industry squeeze rather than a LONGi problem. Second, the company has faced scrutiny over Xinjiang supply-chain links under US UFLPA law; LONGi denies any forced-labour involvement, and UFLPA is US legislation rather than UK, but it’s worth knowing if ethical sourcing matters to you.
The Cell-Tech Ladder: How to Make Sense of the Range
The single best way to understand LONGi’s range is to follow the cell technology, because that’s the thread that runs through every model name. Here’s the ladder, oldest to newest:
- PERC (Hi-MO 5) – the previous-generation workhorse. Reliable, but now beaten on every metric by what came after.
- HPBC 1.0 (Hi-MO 6 / X6) – LONGi’s first back-contact panel, the one that made them a design favourite.
- HPDC (Hi-MO 7) – a high-output utility and commercial cell, built for scale rather than houses.
- HPBC 2.0 (Hi-MO X10 and Hi-MO 9) – the current mainstream tech, more efficient and with better shade handling.
- HIBC (Hi-MO S10) – the newest and most advanced, combining two technologies for record efficiency.
A few plain-English translations so the jargon stops getting in the way:
- Back-contact moves the metal wiring from the front of the panel to the back. More sunlight reaches the cell, the front looks cleaner and all-black, and it handles shade far better.
- N-type is a higher-quality silicon recipe than the older P-type. It degrades more slowly and copes better with heat, so you get more power for longer.
- TaiRay is LONGi’s own stronger wafer – more robust silicon that resists cracking, which means better durability over decades.
- 0BB (zero busbar) removes the visible front wiring lines, shortening the path electricity travels inside the panel and squeezing out a little extra output.
That’s the whole range explained in five rungs. Everything else is detail.
LONGi Range Comparison Table
Here’s the full range at a glance, so you can see where each panel sits before reading the mini-reviews below. Ratings are pulled from our individual reviews of each panel.
| Model | Cell tech | Power | Module eff. | Warranty P/Power | Built for | Rating |
|---|---|---|---|---|---|---|
| Hi-MO 5 | PERC | 405–550W | ~21.3% | 12 / 25yr | Legacy, budget | 3.6/5 |
| Hi-MO 6 / X6 | HPBC 1.0 | 410–460W | 22–23% | 15–25 / 25–30yr | Residential value | 4.0/5 |
| Hi-MO X10 | HPBC 2.0 | 475–500W | up to 24.5% | 15–25 / 30yr | Resi + commercial flagship | 4.5/5 |
| Hi-MO S10 | HIBC | up to 510W | up to 25% | 30 / 30yr | Premium residential | 4.5/5 |
| Hi-MO 7 | HPDC | 580–625W | 22.6–23.1% | 12–25 / 30yr | Utility / commercial | 4.1/5 |
| Hi-MO 9 | HPBC 2.0 | 625–670W | up to 24.8% | 15 / 30yr | Utility flagship | Review pending |
A quick note on the warranty ranges: the product warranty (the bit covering defects and failures) genuinely varies by stock route and exact model, sometimes by 10 years or more. Always confirm the figure for your specific panel in writing before you sign.
The Mini-Reviews
- Cell techHPBC 2.0 · n-type TaiRay · 0BB
- Power475–500W resi (up to 670W commercial)
- Efficiencyup to 24.5% module
- Temp coefficient-0.26%/°C
- Warranty15–25yr product / 30yr power
- Price~£75–95 per panel (ex VAT)
LONGi’s best all-round panel and the default we’d point most UK homeowners toward. The standout feature is shade tolerance – the back-contact design bypasses only the shaded cells rather than dragging down the whole panel, which matters enormously on a typical UK roof with chimneys, dormers or nearby trees. The all-black looks are a bonus from the biggest maker in the business.
Best for: mainstream and premium homes, shaded or space-tight roofs, and commercial installs.
Watch-out: it carries a premium over the X6, and you’ll want to confirm warranty years and MCS status per model.
- Cell techHIBC (HJT + BC)
- Powerup to 510W resi
- Efficiencyup to 25% module / 27.3% cell
- Warranty30yr product / 30yr power
- Pricepremium over X10; per-panel pricing still emerging
The showpiece. It’s the world’s first mass-produced HIBC panel, combining heterojunction and back-contact technology in a single cell, and it’s the highest-efficiency residential panel LONGi makes. The warranty is the strongest in the range at 30 years on both product and power. If you want the best possible efficiency, shade tolerance and safety, this is it.
Best for: premium homes where squeezing maximum output from limited roof space is the priority.
Watch-out: there’s a thin field-data track record behind the long-term projections, it commands a premium price, and UK availability plus MCS certification are still emerging as of 2026. Get a live quote before assuming a price.
- Cell techHPBC 1.0 · P-type, gallium-doped
- Power410–460W
- Efficiency22–23% module (X6 Artist 460W = 23.0%)
- Temp coefficient-0.28 to -0.30%/°C
- Warranty15–25yr product / 25–30yr power
- Price~£52–78 per panel (430W); ~£85–110 (X6 Artist)
The all-black back-contact panel that made LONGi a design favourite, and it’s still excellent – just one generation behind the X10. On the numbers, it does almost everything the X10 does for noticeably less money. Our individual review scores it 8/10, with strong marks for efficiency and brand and a slightly lower mark on price.
Best for: design-led homes and conservation areas where you want premium looks on a value budget.
Watch-out: “Hi-MO 6” and “X6” are the same panel at many UK sellers, so don’t pay a premium thinking one is newer. Warranty terms vary by stock – confirm before you commit.
- Cell techHPBC 2.0 · bifacial dual-glass
- Power625–670W
- Efficiencyup to 24.8% module
- Temp coefficient-0.26%/°C
- Warranty15yr product / 30yr power
- Pricetrade only · sold in pallet / container quantities
The Hi-MO 9 takes the same HPBC 2.0 cell found in the X10 and builds it into a large bifacial dual-glass utility module. It’s a serious panel for serious projects, and because it’s so bankable, it’s well suited to project finance where stakeholders need a rock-solid manufacturer behind the warranty.
Best for: solar farms, large ground-mounted arrays and big commercial roofs.
Watch-out: this isn’t a panel you buy a handful of – it comes in pallet or container quantities. And to clear up the naming: both the 7 and the 9 are utility panels, with the 9 being the newer, higher tier.
- Cell techN-type HPDC · bifacial (~80%) · SMBB
- Power610W (580–625W)
- Efficiency22.6% (up to 23.1%)
- Temp coefficient-0.28%/°C
- Warranty12–25yr product / 30yr power
- Price~£60–85 per panel (ex VAT)
A superb utility and commercial panel – but the wrong tool for a normal house roof, and that’s worth saying plainly. On a big, open roof or ground mount, it’s hard to beat on cost per watt. Our individual review scores it 4.1/5, with the low “residential roof fit” mark reflecting its size rather than any defect.
Best for: barns, ground mounts, and large detached or flat commercial roofs where there’s space to use it properly.
Watch-out: at 2,382mm long and around 33.5kg per panel, it’s impractical on standard pitched roofs, and its bifacial rear gain is wasted on a flush rooftop install.
- Cell techPERC · P-type, gallium-doped · 9BB
- Power405–550W
- Efficiency~21.3% module
- Temp coefficient-0.34%/°C
- Warranty12yr product / 25yr power
- Price~£40–90 per panel (clearance / second-hand)
A very good PERC panel in its day, but now firmly legacy. It’s no longer LONGi’s current line – newer panels beat it on every meaningful measure. The appeal now is purely price.
Best for: budget projects, off-grid setups, sheds, caravans, or owners matching existing panels on an array they already have.
Watch-out: it degrades faster, has a weaker temperature coefficient, and carries a shorter product warranty than everything newer. If a clearance price creeps close to a current N-type panel, buy the newer one instead.
Key Differences at a Glance
- Tech ladder: PERC (5) → HPBC 1.0 (6/X6) → HPDC (7) → HPBC 2.0 (X10, 9) → HIBC (S10). Newer is more efficient and longer-lasting.
- Home vs big-roof split: the 5, 6/X6, X10 and S10 are for homes; the 7 and 9 are utility and commercial panels.
- Efficiency ranking: S10 leads, then X10 and 9, then 7, then 6/X6, with the 5 at the bottom.
- Aesthetics: the back-contact panels (6/X6, X10, S10) give you the cleanest all-black look.
- Warranty trend: product warranties climb as you go up the range, peaking at 30 years on the S10.
- Price-per-watt trend: the 5 is cheapest, the S10 most expensive, with the X10 and 6/X6 offering the best balance for homes.
Award Picks
- Editor’s Choice: Hi-MO X10 – the right call for the majority of UK homes.
- Best Efficiency: Hi-MO S10 – the most output you can get from a LONGi panel.
- Best Value: Hi-MO 6 / X6 – premium looks and performance for less.
- Best Utility: Hi-MO 9 – the flagship for farms and large commercial sites.
- Best Big-Roof Value: Hi-MO 7 – the smart pick for barns and ground mounts.
- Best Budget / Legacy: Hi-MO 5 – cheap watts for off-grid and matching jobs.
Which LONGi Panel Should You Buy?
It basically comes down to your roof and your budget. Here’s the quick logic:
- A normal home? The Hi-MO X10 is your default – or the Hi-MO 6/X6 if you want to save money without losing much.
- The best possible system? Go for the Hi-MO S10, provided you’re happy to pay a premium and accept it’s a newer technology.
- A shaded or small roof? Pick a back-contact panel – the X10, S10 or 6/X6 all handle shade far better than older designs.
- A barn, ground mount or farm? The Hi-MO 7 or Hi-MO 9, depending on scale.
- A budget or off-grid project? The Hi-MO 5, bought as cheap clearance or second-hand.
FAQ
Are LONGi panels any good?
Yes – genuinely. LONGi is the world’s largest solar manufacturer, holds top bankability ratings, and leads the industry on cell technology. Across the range, the panels are efficient, durable and backed by a company that will still be around to honour your warranty.
Which is the best LONGi panel?
For most UK homes, it’s the Hi-MO X10 – our editor’s choice. If you want the highest efficiency available and don’t mind paying for it, the Hi-MO S10 takes the top spot on raw performance.
What’s the difference between the Hi-MO 6 and X6?
For practical purposes, nothing – at many UK sellers they’re the same HPBC 1.0 panel sold under both names. Don’t pay extra assuming one is a newer model.
Is LONGi Tier 1?
Yes. LONGi holds Tier 1 status and an AAA bankability rating, which are the strongest financial-stability markers in the solar industry.
What’s the newest LONGi panel?
The Hi-MO S10, built on world-first HIBC technology. It launched in 2025 and is rolling out across UK distribution through 2026.
Are LONGi panels MCS certified?
Most are, but certification varies by exact model – and newer SKUs can lag. MCS status matters because it determines your eligibility for the Smart Export Guarantee, so always confirm the specific model with your installer before ordering.
How long do LONGi panels last?
Current N-type panels carry 30-year power warranties and typically retain around 88–89% of their output at year 30. In practice, expect a well-installed LONGi system to keep generating for three decades or more.
Hi-MO 7 vs Hi-MO 9 – what’s the difference?
Both are utility and commercial panels, not home panels. The Hi-MO 9 is the newer, higher-tier flagship using HPBC 2.0 cells, while the Hi-MO 7 uses the HPDC cell and tends to be the better-value pick for large roofs and ground mounts.
The safe, market-leading default for UK solar
On the numbers, LONGi is the safe, market-leading default for UK solar – the kind of brand you can choose without losing sleep over whether the warranty will still mean something in 20 years. For most homes, the Hi-MO X10 is the panel to buy. Want the best possible system and happy to pay for it? Go for the S10. Running a big roof, barn or ground mount? Look at the 7 or 9. And treat the Hi-MO 5 as legacy – only worth it cheap or second-hand.
Whichever you choose, buy through a strong MCS-accredited installer, and confirm the exact model’s warranty terms and MCS status in writing before you sign. Then dive into our full review of your shortlisted panel to lock in your decision.
