Module prices have been falling for three years, and 2026 is the year the fall finally shows up in installer margins rather than just headline system costs. Anyone quoting jobs right now is working in a market shaped by Chinese overcapacity, a decisive shift to TOPCon cell architecture, and a domestic installed base still riding the 0% VAT window. This piece looks at where panel prices actually sit, why TOPCon has become the default rather than the premium option, and what a persistent global glut means for the people fitting the panels rather than making them.
Where module prices actually sit in 2026
Chinese-manufactured mono PERC and TOPCon modules have been trading at or below cash cost for most of the last 18 months, a direct consequence of manufacturing capacity that has consistently outpaced global demand growth. Polysilicon, wafer, cell and module capacity across the top Chinese manufacturers now runs well ahead of what the world installs in a year — estimates from trade bodies have put global module manufacturing capacity at more than double annual deployment for several years running. That imbalance doesn’t resolve quickly; factories with sunk capital keep running below cost rather than sit idle, and the result is a module spot price that has kept sliding even as raw polysilicon prices have periodically spiked on the back of production curtailments in China.
For a UK installer, the practical effect shows up less in the sticker price of a pallet of panels and more in the compression between hardware cost and everything else. Panels are now a smaller share of an installed system’s total cost than they were five years ago — inverters, mounting, scaffolding, electrical work and labour haven’t fallen anywhere near as fast. A typical 4kW residential system installed in the UK in 2026 still runs roughly £6,000–£8,000, and a 3kW system around £5,000, numbers that have barely moved even as the modules inside them have got cheaper and more efficient. That’s the story installers need to be telling customers: the panel is no longer the expensive part of the job.
For anyone quoting from scratch or sense-checking a customer’s numbers, thecostofsolar.co.uk’s cost-of-solar-panels breakdown is a useful reference point that tracks these installed costs against the module price trend rather than treating them as the same figure.
TOPCon’s takeover of the mainstream
The technology story is arguably bigger than the price story. TOPCon (Tunnel Oxide Passivated Contact) cells have gone from a premium, efficiency-led option a few years ago to the default mainstream product from most tier-1 Chinese manufacturers in 2026. The reason is straightforward manufacturing economics: TOPCon can be produced on largely the same production lines as older PERC cells with incremental capital investment, it delivers a meaningful efficiency uplift (commercial modules now routinely exceed 22–23% efficiency), and it has better temperature coefficients and lower degradation than PERC.
That last point matters more than marketing copy usually credits. Modern N-type modules — TOPCon, heterojunction (HJT) and back-contact (ABC) designs alike — are specified to degrade at around 0.4% a year, roughly half the rate of older P-type PERC panels, and are warranted for 25–30+ years rather than the 25-year standard that was typical a decade ago. For a UK roof getting somewhere between 850 kWh per kWp a year in the north and over 1,050 kWh per kWp in the sunniest parts of the south, that lower degradation curve compounds into a genuinely larger lifetime yield, not just a marginally higher day-one output figure.
HJT and back-contact modules remain a smaller, higher-cost segment — better temperature performance and aesthetics, useful for space-constrained or premium-positioned jobs, but not the volume product driving the price story. PERC hasn’t vanished, but it is increasingly the clearance-bin option rather than the standard spec, and installers still quoting PERC as a like-for-like alternative to TOPCon are giving customers a worse component for not much of a saving. Anyone advising commercial clients on system specification should be pointing them toward commercialsolarpanelsinstallation.co.uk’s guidance on choosing installers and specifying commercial-scale systems, where module technology sits alongside inverter and mounting choices as a genuine differentiator rather than a footnote.
What oversupply means for installer margins
This is the part of the story that gets less attention than it should. A module glut is unambiguously good for the customer’s bill of materials and unambiguously harder for the installer’s margin, for a few compounding reasons.
First, hardware margin compression. When the wholesale cost of a panel keeps falling, the retail-to-installer markup on that component shrinks in absolute terms even if the percentage stays similar — there’s simply less pound-value to work with on the product line, which pushes installers to recover margin from labour, design and service rather than the kit itself.
Second, price transparency has increased. Customers comparing quotes can now see panel brand and wattage listed on comparison sites and marketplaces, and a widening gap between what a system “should” cost based on module pricing and what’s actually quoted invites harder negotiation. Installers who can’t articulate what they’re charging for beyond the panels — commissioning, warranty backing, structural assessment, G98/G99 grid notification, aftercare — are the ones most exposed to being quoted against on price alone.
Third, and less obvious: oversupply changes stock risk. Distributors holding inventory in a falling-price market are effectively watching their stock devalue in real time, which has driven a shift toward just-in-time ordering and shorter-dated pricing on trade accounts. Smaller installers without strong supplier relationships can find themselves paying yesterday’s higher price while a competitor with better buying terms is already quoting on today’s lower one.
Fourth, quality and warranty risk has risen alongside the volume of budget product entering the market. A glut doesn’t just push down tier-1 pricing, it also floods the market with second- and third-tier manufacturers offering aggressive pricing on modules with less-tested bankability and weaker after-sales support if a manufacturer exits the market. For homeowners this matters for the 25-year warranty that’s meant to back the panel; for commercial buyers financing a system, it matters for lender due diligence. Solar Asset Finance’s approach to funding commercial installations reflects this — lenders increasingly want to see tier-1, bankable module brands specified before they’ll finance a system, which is quietly pushing some of the cheapest product out of the commercial segment regardless of what it costs.
None of this means installer margins are collapsing across the board. It means the margin structure is moving away from “mark up the panels” and toward design, service and finance-attached selling — a shift that rewards installers who’ve built genuine local reputations. ElectriFusion Solutions in Doncaster and South Yorkshire and FLD Electrical, working across Swansea and South Wales, are both examples of installers competing on installation quality, electrical compliance and aftercare rather than trying to win purely on hardware price — which is exactly where the market is pushing the whole trade.
The 0% VAT window is compressing the calendar, not the price curve
It’s worth separating two things that get conflated in trade conversations: module price trends and the UK’s 0% VAT treatment on residential solar and battery storage, which runs until 31 March 2027 before being scheduled to revert to 5%. The VAT relief has nothing to do with manufacturing oversupply — it’s a domestic fiscal policy decision — but it interacts with the pricing story in a way installers should be alert to. As the 2027 deadline approaches, expect a seasonal bunching of installation demand in late 2026 and early 2027 as homeowners try to lock in the saving, regardless of where module spot prices sit at the time. That’s a scheduling and capacity-planning problem for installers, not a pricing one, but it will collide with whatever the module market is doing at the time and installers who haven’t planned crew capacity for a pre-deadline rush will be turning away work at exactly the point margins might otherwise be recovering.
On the commercial side, VAT relief doesn’t apply in the same way, and business buyers are instead weighing capital allowances, financing structures and, increasingly, Power Purchase Agreements that remove capital cost from the equation altogether. Solar Power Purchase Agreements’ explainer on how PPA-financed commercial systems are procured is a good reference for installers fielding commercial enquiries where the customer’s real question isn’t “how much are the panels” but “how do we pay for this without capex”.
Reading the export-price and grid side of the ledger
Module cost is only one input to the customer conversation. Smart Export Guarantee rates vary meaningfully by supplier — commonly quoted in the 12–20p/kWh range at the better end rather than any fixed national rate — and typical import electricity sits around 25p/kWh under the current Ofgem price cap, though this moves. Getting these two numbers right, alongside a realistic yield assumption of roughly 850 kWh per kWp annually (more in the south), matters more to a customer’s payback calculation than a few pence per watt of module price movement. MCS certification remains the non-negotiable gatekeeper here — no MCS installation, no SEG eligibility — so any installer chasing volume through cut-price, non-badged fitters is setting customers up to lose export income entirely.
For commercial and agricultural buyers specifically, the module price story sits alongside genuinely different economics: roof area is larger, self-consumption during daytime operating hours is typically higher, and battery attach rates are lower because the payback case for storage is weaker when most generation is used on-site rather than exported. Solar Panels For Farms and Solar Panels For Warehouses both cover this segment, where oversupply-driven module pricing is arguably having its biggest structural effect — commercial-scale systems at roughly £900–£1,200 per kWp are now genuinely payback-competitive in a way they weren’t three or four years ago, largely because the module component of that per-kWp figure has fallen furthest.
What this means for the rest of 2026
Expect module prices to stay under pressure rather than recover sharply — Chinese capacity rationalisation has been talked about for several consecutive years without a decisive cut, and a genuine supply-demand rebalance looks more like a multi-year grind than a 2026 event. TOPCon will keep extending its share at the expense of PERC, HJT and ABC will hold a premium niche, and the installers who do best won’t be the ones chasing the lowest landed module cost — they’ll be the ones who’ve built a service, finance and compliance proposition solid enough that the panel price barely features in the sales conversation. For trade-side market data and installer positioning through the rest of the year, Solar Weekly’s UK solar industry 2026 overview is tracking the deployment and capacity figures behind this piece as they update.
The practical takeaway for installers: stop competing on panel price, because that fight is being decided in Chinese factories, not on UK doorsteps. Specify TOPCon as standard, be explicit with customers about why lower degradation and longer warranties matter more than a marginally cheaper PERC panel, and build the parts of the quote — design, compliance, finance access and aftercare — that oversupply can’t commoditise.