Anyone tried those cheap 100W panels from eBay — worth the risk or false economy?

Bought three of them last summer for the shepherd's hut project. Two are still going fine, one developed a hotspot within about four months — you could actually see it delaminating in the corner. Annoying but not a disaster at that price point.

The thing is, with cheap panels you're basically gambling on QC consistency rather than getting a genuinely inferior product. The cells inside are often the same grade as the branded stuff, it's the encapsulation and junction boxes where corners get cut.

A few things I'd actually check before buying:

• Junction box quality — if it looks like it'll snap off in a stiff breeze, it probably will
• Seller feedback specifically on solar panels, not just general feedback
• Whether they'll honour returns — some won't budge if a panel degrades rather than fails outright

For a cabin or hut setup where you're not relying on every single watt, I think the risk is manageable. I wouldn't go near them for a primary system where I needed reliability. My Renogy panels on the main array have been rock solid by comparison, but they cost nearly double.

Honestly the worst part isn't if one fails — it's the uncertainty. You find yourself wondering whether that voltage drop is the panel, the controller, the wiring...

Anyone else mixing cheap panels with better branded ones on the same array? Curious whether people are seeing issues with mismatched performance pulling things down.

@MarshLover that delaminating corner is the classic tell — thermal imaging on cheap panels often shows hotspots from the start, you just can't see them yet.

I've gone down this road with the garden office and honestly the maths rarely works out. A decent Renogy or even a budget Rich Solar panel might cost 30-40% more but you're not gambling on which one fails first.

The real hidden cost is the labour — remounting, rewiring, rebalancing your array when one drops out. That eats your "saving" fast.

My rule now: if there's no verifiable IEC 61215 certification and a real warranty you can actually claim, it goes in the bin. Plenty of eBay sellers are UK-registered but the warranty support is essentially nonexistent once something goes wrong.

Two from three isn't terrible odds — until it's your one that fries something downstream.

Great thread this. I've had mixed results too — bought a job lot of five cheapies a couple of years back for a static caravan install, and honestly three of them are still pulling decent watts. The other two I'd have binged in the skip by month six.

What I'd add to what @JackeryNerd is getting at: the real issue isn't just the panels failing, it's where they fail. A hotspot in a series string can drag down your whole array's output long before it becomes visibly obvious. Stick a bypass diode check on your list if you're running these budget ones — some of the cheap panels cut corners there specifically.

For a shepherd's hut at low wattage, I'd probably still risk it personally, but I'd wire each panel independently rather than series, and keep an eye on individual output. Makes fault-finding much easier.

@MarshLover the hotspot issue you're describing is almost certainly a failed bypass diode — when they go, current reroutes through a section of cells and you get that localised heating which eventually cooks the encapsulant.

For what it's worth, I've run a mix of Renogy and unbranded panels on my shepherd's hut here in the Borders. The Renogy units have been flawless over three seasons; two of the no-name 100W panels I got as a trial developed measurably reduced output within eighteen months (checked with a clamp meter on a clear day against spec).

My rule of thumb now: cheap panels can work as supplementary capacity where a partial failure isn't critical, but for your primary array feeding batteries — especially through a Victron MPPT — just buy known-spec panels. The price delta is smaller than people think when you factor in replacement costs.

@MarshLover had almost identical with my narrowboat setup — bought a pair of no-name 100W panels off eBay, one went dodgy within six months. Lesson learned.

Switched to Renogy for the cabin after that and honestly the price difference isn't as dramatic as people think once you factor in the hassle of warranty faff with random eBay sellers who've often vanished by the time something goes wrong.

For a shepherd's hut one-off project, maybe roll the dice. For anything you're relying on daily? Just buy decent kit. Victron, Renogy, even the better Fogstar bundles — you know what you're getting.

The real false economy is your time chasing refunds on a marketplace where the seller has 47 feedback and a name like "SolarPro2019_UK."

@BordersExplorer is right about the bypass diodes, but there's a deeper issue nobody's mentioned yet — the encapsulant on these budget panels is often EVA that hasn't been properly cross-linked during lamination. Once moisture ingresses (and in the UK, it will), you get PID — potential induced degradation. Efficiency nosedives silently before anything visible happens.

I've tested three "100W" eBay specials with my clamp meter on a clear July day. Best one hit 78W. Worst managed 61W. That's not a panel, that's a disappointment with a junction box.

For a shepherd's hut or static setup, Renogy panels from their official store are only marginally more expensive and actually warrant testing. Or watch for Fogstar clearance deals.

The false economy calculation becomes obvious once you're replacing a £35 panel every 18 months.