If you've been quoted Trina Vertex S panels, or spotted them going cheap, you're right to pause before signing. The Vertex S is a decent panel, but it's an older one – a legacy P-type PERC module that Trina has since replaced with the newer Vertex S+. On the numbers, the S+ beats it on efficiency, warranty and how long it lasts. So the Vertex S only really makes sense when it's meaningfully cheaper.
This review gives you the honest version: what the Vertex S actually is, who it still suits, what it costs, and exactly how it stacks up against the S+ you'll be offered on most 2026 quotes. We haven't lab-tested these ourselves – what you're getting is our read on the datasheet, the warranty, and what the panel is for.
Here's what's inside: quick answers, full specs, UK pricing, the all-important S versus S+ comparison, and a clear steer on which one to buy.
- It's a legacy budget panel, not the current default. Launched in 2021, the Vertex S has been superseded by the Vertex S+ (and now the S+ G3). We rate it only where it's clearly cheaper than the S+.
- Efficiency tops out at 21.8%. That's solid but a step behind the S+ at 22.3–22.8%, so you'll need a little more roof space per kilowatt.
- The warranty is shorter than the S+. You get 15 years on the product and 25 years on power, versus 25 and 30 years on the S+.
- Pricing is its main appeal. Expect around £106–150 ex VAT per 425W panel at trade, with a fully installed 4kW system landing at £6,500–9,500.
- The maker is rock-solid. Trina is a Tier 1 manufacturer with a 100% BNEF bankability rating – so the company behind your 25-year warranty is very much still around.
Our Verdict & Rating
- Cheap – one of the lowest-cost ways to get a Tier 1 brand-name panel on the roof
- Backed by a strong maker – Trina holds a 100% BNEF bankability rating and Tier 1 status, so warranty claims stay viable
- Compact and light at 21.8kg, which suits smaller or awkwardly shaped roofs
- Widely compatible with mainstream inverters, optimisers and mounting systems
- Proven and reliable – a well-established panel with a solid track record
- Lower efficiency at 21.8% versus 22.8% on the S+, so it needs a little more roof space per kilowatt
- Faster degradation – 2% in year one and 0.55% a year, versus 1% and 0.4% on the S+
- Shorter product warranty at 15 years, against 25 on the S+
- Some models discontinued – stock is finite and shrinking
- Naming confusion in the market makes it easy to buy the wrong thing
The Vertex S was a genuinely good panel in its day – a dependable, well-made PERC module from a Tier 1 maker. But its day was 2021, and the newer Vertex S+ now beats it on efficiency, degradation and warranty, which is exactly why it's become budget and clearance stock. For a shed, an off-grid cabin, or matching an existing Vertex S array, it's a sensible, honest choice. For a brand-new home system, pay the modest premium for the S+ – over 25 years the extra power and longer warranty are worth far more than the upfront saving.
Quick Answers
- What is the Trina Vertex S?
- A monocrystalline solar panel using older P-type PERC cell technology. It's Trina's entry-level residential module, launched in 2021, delivering 390–435W depending on the exact model.
- Who is the Vertex S for?
- Budget-focused buyers, off-grid and RV or marine setups, and anyone matching panels to an existing Vertex S array. If you're speccing a brand-new home system, the Vertex S+ is the better call.
- Is the Trina Vertex S worth buying in 2026?
- Only if it's noticeably cheaper than the Vertex S+. It's a dependable panel, but you're accepting lower efficiency, faster ageing and a shorter product warranty in exchange for the lower price. That trade works for a shed, an off-grid cabin or a tight budget – not for a premium new install.
- How does it compare to the Vertex S+?
- The S+ uses newer N-type technology, dual-glass construction, hits higher efficiency, degrades more slowly, and carries a longer warranty. On the numbers, the S+ wins on almost every measure except upfront price.
What Is the Trina Vertex S?
The Vertex S is a residential solar panel made by Trina Solar, one of the world's largest manufacturers. It uses P-type PERC cells – the mainstream premium technology of roughly 2018 to 2022. In plain terms, PERC adds a reflective layer to the back of each cell so light that would otherwise slip through gets a second chance to become electricity. Good technology for its day, now bettered by newer N-type cells.
The "S" tag means it's the smaller rooftop version of Trina's larger Vertex platform. It's built with half-cut cells, multi-busbar wiring and a single sheet of glass over a backsheet, all held in an anodised aluminium frame. That makes it a compact, easy-to-handle panel that plays nicely with mainstream inverters, optimisers and mounting kits.
Here's the important part for buyers: the Vertex S is now a legacy panel. Trina replaced it with the Vertex S+ in 2022, and launched the third-generation S+ G3 in March 2026. Some Vertex S models have already been discontinued, though distributor stock still circulates. So while you can still buy one, it isn't the panel Trina is pushing – and it isn't the one most installers will quote you by default.
Who the Vertex S Is For Now
The Vertex S makes sense for a narrower group of buyers than it did in 2021. It's a strong fit if you are:
- On a tight budget and want the cheapest way to get a reliable, brand-name panel on the roof.
- Building an off-grid, RV, marine or shed setup where the last few percent of efficiency simply doesn't matter.
- Matching panels to an existing Vertex S array – adding to what you already have, where mixing wattages would cause problems.
- Working with a large, unshaded roof where you've got the space to fit a slightly lower-efficiency panel without running out of room.
Who Should Choose the Vertex S+ Instead
If you're planning a brand-new home installation, the Vertex S+ is the better buy for most people. You get more power from the same roof, slower degradation, and a longer warranty – and over 25 years, that gap adds up to more electricity and more peace of mind. The S+ is the standard 2026 residential quote for a reason.
The simple rule: buy the Vertex S only when it's clearly cheaper than the S+. Otherwise, pay the modest premium and get the newer panel.
Trina Vertex S Full Specifications
These figures are for the TSM-DE09R.08, the current top variant at 415–435W. One thing to watch: the Vertex S is a multi-generation series, so always confirm the exact model code against its own datasheet, as the numbers shift between versions.
| Specification | Detail |
|---|---|
| Power range | 415–435W (this variant); 390–435W across the series |
| Max module efficiency | 21.8% |
| Cell type | P-type mono PERC, half-cut, multi-busbar |
| Cell count | 144 |
| Temperature coefficient (Pmax) | -0.34%/°C |
| Dimensions | 1,762 × 1,134 × 30mm |
| Weight | 21.8kg |
| Glass | 3.2mm, anti-reflective coated, heat-strengthened |
| Frame | 30mm anodised aluminium |
| Junction box | IP68 rated |
| Max system voltage | 1,500V DC |
| Operating temperature | -40°C to +85°C |
A couple of these matter more than the rest for a UK home. The temperature coefficient of -0.34%/°C tells you how much output the panel loses as it heats up – and it's worth knowing that newer N-type panels sit closer to -0.29%, so they cope a little better on warm days. At 21.8kg and just under 1.8m long, it's a genuinely compact panel that suits fiddly or broken-up roofs, which is one of the Vertex S's quiet strengths.
Warranty: What You're Actually Covered For
Here's where the age of the panel shows. The Vertex S comes with a 15-year product warranty (covering faults and defects) and a 25-year power warranty (guaranteeing output). That's a fair deal, but it trails the S+, which offers 25 and 30 years respectively.
The degradation figures tell the same story:
- First-year drop: 2.0%
- Annual drop after that: 0.55%
- Guaranteed output at year 5: 98.0%
- Guaranteed output at year 25: 84.8%
In plain terms, after 25 years your Vertex S is warranted to still produce nearly 85% of its original output. That's respectable. But the S+ holds roughly 87% at year 30, because it fades more slowly (around 1% in year one, then 0.4% a year). Over the life of the system, that's a meaningful chunk of extra electricity.
Some third-party listings quote a 2.5% first-year drop and around 0.73% a year for certain Vertex S models. The official DE09R.08 datasheet says 2% and 0.55%. If the numbers you're shown don't match, check exactly which model code the seller means before you rely on any figure.
Trina Vertex S Price UK 2026
Working out what you'll actually pay is trickier than it should be, because the Vertex S sells across trade, retail and off-grid channels at quite different prices. Here's the realistic picture, and remember panel pricing moves month to month, so treat these as a starting point.
- Trade, 425W: roughly £106–150 ex VAT per panel, depending on the exact variant and distributor (the DE09R.08 black-frame lists around £106 ex VAT at UK wholesalers, up to about £127 ex VAT / £152 inc elsewhere).
- Retail, 410W full black: around £160 ex VAT (£192 inc VAT) from UK sellers like Renugen.
- Retail, 390W full black: around £150 ex VAT (£180 inc VAT).
- Fully installed 4kW system: £6,500–9,500 at 0% VAT, with most quotes landing at £7,000–8,500.
For context, the Vertex S+ sits at a modest premium over the S through UK trade channels. That's the number that matters: if the S is only a few pounds per panel cheaper, the S+ is the smarter buy. If there's a genuine gap – clearance stock, an off-grid pallet deal – then the S starts to earn its place. Worth noting: residential solar currently benefits from 0% VAT in the UK, though it's always wise to confirm the relief is still in place before you commit.
Vertex S vs Vertex S+ vs S+ G3
This is the comparison that decides your purchase, so here it is at a glance. The headline: the S+ is the newer, better panel, and the S+ G3 is newer still.
| Feature | Vertex S | Vertex S+ | Vertex S+ G3 |
|---|---|---|---|
| Cell type | P-type PERC | N-type i-TOPCon | N-type, 3rd gen |
| Construction | Single glass + backsheet | Dual glass | Dual glass |
| Launched | 2021 | 2022 | March 2026 |
| Power range | 390–435W | 425–455W | Higher than S+ |
| Module efficiency | 21.0–21.8% | 22.3–22.8% | Above S+ |
| First-year degradation | 2.0% | 1.0% | – |
| Annual degradation | 0.55% | 0.4% | – |
| Product warranty | 15 years | 25 years | – |
| Power warranty | 25 years | 30 years | – |
The two differences that matter most to you are cell type and warranty. The S uses older P-type PERC; the S+ uses newer N-type i-TOPCon, which degrades more slowly and handles heat better, so you get more power for longer. And the S+ gives you an extra 10 years of product cover and 5 more years of power cover – for a fixture that sits on your roof for decades, that's real reassurance, not a spec-sheet footnote.
Buying Considerations
If you've decided the Vertex S fits your plans, a few checks will save you grief.
- Watch the naming – this is the big one. The Vertex S and S+ get muddled constantly, and some sellers mislabel the newer S+ as the older S. Two quick ways to tell them apart: check the cell type (PERC means S, N-type means S+) and the glass (single glass means S, dual glass means S+). If a listing says something like "Vertex S Dual Glass 425W," that is not a genuine Vertex S – dual glass is an S+ feature, so the seller has either mislabelled it or is describing a different panel.
- Always confirm the exact model code. Efficiency, wattage, warranty and degradation all differ between the DE09.05/.08 and the newer DE09R.05/.08 versions. Pin down the code before you rely on any figure.
- Check stock before you count on it. Some key Vertex S models are listed as no longer in production, even though distributor stock still floats around. Confirm availability with a supplier before you plan a system around it.
- Confirm MCS certification. This is what makes your system eligible for the Smart Export Guarantee – the scheme that pays you for the electricity you send back to the grid. Verify the specific panel and your installer are MCS-registered before ordering.
Trina Vertex S FAQs
Is the Trina Vertex S a good panel?
Yes, for what it is – a reliable, entry-level panel from a top-tier maker. It's just no longer the best Trina offers. We rate it as a genuine budget choice, but for a new home install the Vertex S+ is the better buy.
What's the difference between the Vertex S and Vertex S+?
The S+ uses newer N-type cells, dual-glass construction, hits higher efficiency (up to 22.8% versus 21.8%), degrades more slowly, and comes with a longer warranty. The S is the older, cheaper P-type panel.
How long do Trina Vertex S panels last?
The power warranty runs 25 years, and the panel is guaranteed to retain 84.8% of its output at year 25. In practice, a well-installed system will keep generating well beyond that.
How much does a Trina Vertex S cost in the UK?
Around £106–150 ex VAT per 425W panel at trade, with a fully installed 4kW system typically costing £6,500–9,500 at 0% VAT.
Are Trina Vertex S panels still available?
Some models have been discontinued, but distributor stock still circulates through UK sellers. Always confirm current availability before planning a system around them.
Is Trina a reliable manufacturer?
Very. Trina is a Tier 1 maker founded in 1997, with a 100% BNEF bankability rating and cumulative shipments above 292GW. The company behind your warranty is stable and here for the long haul.
A dependable panel – but only when it's cheaper
The Trina Vertex S was a strong panel in its day, and it's still a dependable, well-made module from a manufacturer you can trust. But its day was 2021, and the newer Vertex S+ now beats it on efficiency, degradation and warranty. For most people planning a new home system, the Vertex S+ is the panel to buy – the modest price premium buys you more power over a longer, better-guaranteed life.
The Vertex S earns its place in one situation: when it's genuinely cheaper. For a tight budget, an off-grid or shed setup, or matching an existing array, it's a legitimate, sensible choice – just confirm the exact model code, check the stock is real, and make sure you're not being sold a mislabelled S+.
Your next step: get at least three quotes from MCS-accredited installers, ask each to price both the Vertex S and the S+ side by side, and compare the cost per installed kilowatt. If the S+ is only a little dearer, take it – and if the S is the clear budget winner for your project, buy it with confidence.
