New panels got cheap. Second-hand ones didn’t.
Used solar panels sell for roughly 10p to 35p per watt in the UK. Mainstream new panels were trading at about 13p to 16p per watt in mid-2026. For most buyers, the discount that made second-hand worth the risk has already gone.
Most advice about second-hand solar panels was written when a new panel cost £200. It quotes £50 to £70 for a used one, calls that half price, and stops there. The arithmetic has moved. New panel prices fell hard between 2023 and 2026 while second-hand prices, set by sellers looking at old retail figures, barely moved. On a per-watt basis, a lot of used panels are now more expensive than new ones.
- Compare pence per watt, never pounds per panel. A £50 used 250W panel is 20p/W. A £68 new 450W panel is 15p/W, and it makes 80% more electricity.
- The panels are the cheap part of an install. On a £6,500 twelve-panel job the modules are worth roughly £850 to £1,700. Halving that saves less than most people expect.
- Second-hand panels cannot be MCS certified after the fact, which rules out almost every export tariff. Octopus runs a non-MCS route for £250, but acceptance is not guaranteed.
- Roof area is the real constraint. Old low-efficiency panels cost you around a third of your potential output from the same roof, worth about £250 to £300 a year.
- They still make sense in three places: replacing a failed panel in an old array, off-grid and outbuilding use, and ground mounts where space is free.
The number that decides it
Price per watt. That single figure settles most of this question before you look at condition, warranty or anything else, and almost nobody selling second-hand panels quotes it.
A panel’s price only means something next to its output. A 250W module from 2012 and a 450W module from 2026 both take up a similar patch of roof, both need the same brackets and the same electrician. One makes 80% more electricity than the other. So the useful comparison is not £50 against £70. It is 20p per watt against 15p per watt.
| What you’re buying | Typical price | Price per watt |
|---|---|---|
| Used 250W, 12-14 years old, private sale | £40-£60 | 16p-24p |
| Used 300-370W, 5-10 years old | £55-£85 | 15p-25p |
| Used panel under 5 years old | £90-£150 | 20p-35p |
| Ex-farm bulk lot, 10+ years, pallet quantity | £20-£45 | 10p-20p |
| New mainstream N-type, 430-500W | £62-£79 ex VAT | 13p-16p |
Only one category on that table reliably undercuts a new panel: old modules bought by the pallet. Those are also the ones with the least remaining life, the worst efficiency and no realistic route to a warranty claim. Everything else in the second-hand market is now priced at or above new.
The figures behind the “£50 to £70 a panel is half price” line date from a period when a new domestic panel cost £180 to £250. Mainstream new panel prices fell through 2025 and 2026, and matched-model tracking showed a further 3.6% drop between April and July 2026 alone. Any second-hand guidance written before mid-2025 is comparing against a price that no longer exists.
Four different things sold as “used”
“Second-hand solar panel” covers four products with different prices, different risk and different sensible buyers. Working out which one you’re being offered matters more than haggling.
| Type | Where it comes from | What to expect |
|---|---|---|
| Ex-farm, repowered | Solar farms replacing 2010-2014 modules with higher-output ones while the site permit allows | Sold in pallets of 25 to 40, often 500+ units minimum. Consistent batch, known history, low price per watt. Rarely sold as singles. |
| Ex-domestic removals | Roof replacements, extensions, house sales, systems taken off before re-roofing | Singles and small lots on Gumtree, eBay and Facebook. Handling is the risk: panels stacked in a van and leaned against a shed pick up cell cracks that don’t show. |
| B-grade and cosmetic seconds | Factory output that failed a visual check, not a performance one | Never installed, full output, no manufacturer warranty. Usually the best value in this list if you can find them in small quantities. |
| New old stock | Cancelled projects, liquidated stock, discontinued models | Unused and boxed, but obsolete specifications. Check the date code, not just the condition. |
Refurbished is a fifth label and it means whatever the seller wants it to mean. There is no UK standard behind the word. Ask what was actually done: junction box replaced, diodes tested, output measured under load, or just washed and photographed.
What used panels cost in 2026
Single used panels on the private market run from about £30 to £150, clustering around £50 to £70. Published second-hand guidance puts panels under five years old at 20p to 35p per watt, five to ten years old at 15p to 25p, and over ten years at 10p to 20p. Bulk ex-farm lots go lower still, but usually only in pallet or container quantities.
The bigger point is what share of a solar installation those panels represent. Take a twelve-panel roof system quoted at £6,500 fully installed. At trade prices the modules in it are worth around £850. Even at a retail markup they might be £1,700 of the quote. The other £4,800 to £5,650 is the inverter, mounting rail, DC and AC cabling, isolators, scaffolding, two days of labour, DNO notification and certification. None of that gets cheaper because your panels came off a barn roof.
So the realistic saving on a supply-your-own-panels job is £600 to £1,100 on a £6,500 project, assuming you can find an installer willing to fit modules they didn’t supply. Most won’t, because the workmanship warranty and their MCS registration both depend on the products used.
VAT works against you here. The 0% rate on solar runs to 31 March 2027, but it applies to a single supply-and-install contract. Buy panels separately from a VAT-registered trader and they are standard-rated at 20%. A private sale carries no VAT at all, which is one of the few structural advantages second-hand still has.
What you give up
Four things, and the export tariff is the expensive one.
Export payments
The Smart Export Guarantee pays you for electricity you send back to the grid. Almost every supplier requires an MCS or Flexi-Orb certificate, which covers both the installer and the products fitted. Panels have to be on the approved product list, and an installation built from second-hand modules cannot be certified retrospectively. A 4kW system exporting around 1,800kWh a year is worth roughly £200 to £250 annually on a decent tariff. Over twenty years that dwarfs anything you saved on the panels.
There is one exception, and most guides miss it. Octopus Energy operates a route for systems without MCS certification: you submit your DNO acceptance letter, Electrical Installation Certificate and Building Regulations evidence, pay a £250 assessment fee, and need a working smart meter. Applicants report being placed on the basic SEG rate initially. Acceptance is not guaranteed and the process runs to weeks rather than days, so treat it as a possibility rather than a plan.
Warranty
Panel product warranties are typically 12 to 25 years and performance warranties 25 to 30, but they are held by the original purchaser and tied to the original installation. Buy second-hand and you have neither. If a panel fails in year three you replace it, and you now need a matching module, which sends you back to the same used market.
Paperwork that follows the house
Electrical work on a solar installation is notifiable under Part P in England and Wales, and every grid-connected system needs a G98 notification or G99 approval from your Distribution Network Operator. Those requirements apply whatever the panels cost. A conveyancing solicitor will ask for the certificates when you sell, and a missing MCS certificate is the sort of thing that produces awkward questions late in a sale. Read the Part P and building regulations rules before you commit to a route.
Insurance
Tell your buildings insurer about any solar array. Some will want to see certification for a roof-mounted system, and an uncertified installation of unknown-provenance modules is a harder conversation than a standard MCS job. Make the call before install day, not after a claim.
Roof space, not panel price, is the constraint
This is the cost nobody puts a number on, and it is larger than the saving.
You do not have unlimited roof. You have one pitch, usually 15 to 25 square metres of it worth using. A 2012-era 250W panel occupies about 1.65m² and works out at roughly 152 watts per square metre. A 2026 450W panel occupies about 1.99m² and delivers roughly 226 watts per square metre. Same roof, same scaffolding, same day’s labour.
Run 20m² of usable roof through both. Twelve old panels give you 3.0kWp. Ten new ones give you 4.5kWp. That gap is 1.5kWp you can never get back without stripping the roof and starting again. In the Midlands, 1.5kWp is around 1,300kWh a year. At a blend of self-consumption and export it is worth something like £250 to £300 annually, every year, for the life of the system.
Save £900 on panels, lose £275 a year in output. The trade breaks even inside four years and keeps losing after that. This is why used panels make sense on ground mounts and outbuildings, where you can simply add more of them, and stop making sense on a roof, where you can’t. If roof area is your limit, paying more per panel for higher efficiency is the correct move, not less.
When used panels are the right call
Three situations, and the first one is the strongest case in this entire article.
Replacing a failed panel in an older array
If one module in a 2013 string has failed, you cannot drop a modern 450W panel into the gap. Panels wired in series are held back by the weakest one, and mismatched voltage and current will drag the whole string. A matching second-hand module of the same model is often the only sensible repair, and it is usually cheap because nobody else wants a 250W panel. This is the one case where the second-hand market solves a problem new panels cannot. See our guides on what to do with a broken panel and finding the fault first, because a dead panel is not always a dead panel.
If your system is on the Feed-in Tariff, contact your FiT licensee before changing anything about the array. Like-for-like repair and capacity changes are treated differently, and getting this wrong on an early-2010s system can put a valuable index-linked income stream at risk.
Off-grid and outbuildings
Sheds, workshops, stables, allotment huts, boats, campervans and remote gates. No grid connection means no DNO notification, no MCS, no export tariff to lose. Efficiency barely matters because you are not short of space and you are usually charging a battery rather than chasing peak output. A £40 panel that makes 200 real watts is fine here. This is where second-hand has always worked and still does.
Ground mounts and fences with room to spare
Paddock, large garden, farm building. If you can compensate for low efficiency by adding two more panels, the roof-area argument disappears and price per watt is all that counts. Bulk ex-farm lots at 10p to 15p per watt are worth looking at. Budget for the extra mounting frame and cabling that more panels require, and remember that ground-mounted systems have their own planning and structural considerations.
Buy in one batch, same model, same age, so the string is electrically matched.
Test under load in daylight before money changes hands.
Ask why the panels came off. Repowering and a re-roof are good answers. “Not sure” is not.
Buy panels with any crack in the glass. Cracked glass is a recycling job, not a bargain.
Mix models or wattages within a single string.
Assume an electrician will connect customer-supplied used modules. Ask first.
Plug-in solar doesn’t change the answer
Plug-in solar became legal in Great Britain on 27 August 2026 under SI 2026/848. A compliant device can output up to 800W AC at the plug, fed by up to 2,000W of panels, with no installer required. Northern Ireland is not covered, batteries are excluded from this first phase, and it is one device per household.
It reads like an opening for cheap used panels. It isn’t. The legal route applies to a complete product certified against the UK Plug-in Solar Device Interim Product Specification, covering the panels, the micro-inverter, the lead, the plug, the mounting arrangement and the labelling as one approved assembly. Bolting a Gumtree panel onto a kit puts you outside that definition. A retailer confirming the inverter is G98-registered is not the same as the whole kit being compliant.
If you already have a roof system, adding a plug-in device is not automatically free of paperwork. The simple-connect threshold of 3.68kW per phase is cumulative across the property, so an extra 800W can tip the whole house into a formal G99 application taking weeks. Check your existing inverter rating before buying anything.
How to check a panel before you pay
Twenty minutes with a multimeter separates a working module from scrap. Go on a bright day, take the seller’s model number in advance and look up the datasheet before you arrive.
Serial number present and legible, model number matching the listing, rated Voc, Isc and Pmax noted. No readable label means no way to verify anything. Walk away.
Any crack or chip in the glass is a hard no. On the back, look for tears, bubbling, chalking or peeling. Backsheet failure was a known problem on some 2010-2014 modules and it lets moisture in.
Brown or yellow patches mean overheating. Dark spidery lines are microcracks, usually from bad handling after removal. Snail trails and mismatched cell colour both point to cell damage under the glass.
Multimeter on DC volts across the two leads, in full sun. A healthy panel reads within about 10% of its rated Voc. A big shortfall means cell or internal wiring damage.
Voltage alone hides weak output. Connect a resistive load or a charge controller and measure current. Aim for 80% or more of nameplate power in good sun. Below that, the panel is worth scrap value.
Heat marks, cracked housings, resoldered joints and mismatched connector brands are all reasons to stop. Cheap non-genuine MC4 connectors mated to real ones are a documented fire risk and are not acceptable in a fixed installation.
Buying private means no returns and no consumer protection worth the name. Everything you fail to check is yours to keep.
Selling panels you already have
Coming at this from the other direction, because plenty of people search this term with panels to shift rather than buy.
Working modules with intact glass and readable labels sell locally for £20 to £60 each, faster if you have a matched set and can show a load test on video. Price at 10p to 15p per watt to move them quickly. Panels with cracked glass have no resale value and should go for recycling rather than to landfill: solar panels fall under WEEE rules, and most manufacturers and larger installers have take-back arrangements. If you are removing panels as part of an upgrade rather than a repair, read upgrading an older system first, and check your FiT position before anything comes off the roof.
Are second-hand solar panels worth it in the UK?
For a grid-connected roof system, usually not. New mainstream panels now cost about the same per watt, come with warranties, and allow MCS certification and export payments. For off-grid use, outbuildings and ground mounts with spare space, they still stack up.
How long do used solar panels last?
Panels are built for 25 to 30 years and typically lose around 0.5% of output a year after a larger first-year drop. A healthy 2012 module should still be near 90% of nameplate. The problem is that removal and transport damage does not show up on a voltage test, so remaining life on a used panel is a genuine unknown.
Can I get SEG payments with second-hand panels?
Not through the standard route. SEG tariffs need an MCS or Flexi-Orb certificate, which requires certified products and a certified installer at the time of installation, and cannot be applied retrospectively. Octopus operates a separate non-MCS assessment costing £250 with no guarantee of acceptance.
Will an installer fit panels I supply myself?
Most MCS-certified installers will not. They cannot register the job, cannot stand behind products they haven’t sourced, and their workmanship warranty and insurance are built around known equipment. Independent electricians sometimes will, for off-grid or non-notifiable work.
Do used panels qualify for 0% VAT?
Only inside a single supply-and-install contract with one company, which is exactly the arrangement second-hand buying tends to break. Panels bought on their own from a VAT-registered trader carry 20%. A private sale carries none. The zero rate runs to 31 March 2027.
Is it safe to mix old and new panels?
Not within the same string. Series-wired panels are limited by the weakest module, so mixing wattages or ages throws away output. Separate strings on separate MPPT inputs, or micro-inverters, can handle mixed panels, but that is a design decision for the inverter stage rather than something to sort out afterwards.
The discount stopped being big enough
Second-hand solar panels made obvious sense when a new module cost £200 and a used one cost £60. New mainstream panels now sell for £62 to £79 ex VAT, and used panels are still priced against the old market. On a per-watt basis, most of the second-hand stock in the UK is no longer a saving.
The panels were never the expensive part anyway. Scaffolding, labour, the inverter and certification make up the bulk of an installed system, and none of it moves because your modules are pre-owned. What does move is your output: filling a fixed roof with low-efficiency panels costs you around a third of what that roof could produce, worth more each year than you saved once.
Buy used to repair an old array, to power a shed or boat, or to fill a field where space is free. For a roof system you intend to keep for twenty years, get quotes for new panels from MCS-certified installers and compare the whole job, not the panel price.
Working out the whole-system numbers first is the sensible next step: our guides to what solar panels cost in 2026, the costs that don’t appear on the headline quote, and whether solar is worth it for your home cover the arithmetic this decision actually turns on.
METHODOLOGY: New panel pricing from UK trade and retail listings tracked to July 2026. Second-hand pricing from published UK second-hand guidance and current private-sale listings, August 2026. Output modelling assumes 20m² of usable south-facing roof and typical Midlands yield of around 870kWh per kWp.
DISCLAIMER: All prices indicative and subject to change. We do not provide financial advice. The Smart Export Guarantee is administered by Ofgem; export tariff rates and eligibility are set by individual suppliers. VAT treatment depends on the structure of your contract and should be confirmed with your installer.
