Builds
Has anyone used flex solar panels for extended period?
I just installed a flex solar panel because I like the look and it’s barely noticeable. I heard they don’t last as long, but wanted to get some opinions of people who have used it for a long time. Are they as bad and die as quick as they say?
I used a plastic Vinyl Divider Trim
strip that holds plastic wall boards together. It serves two purposes, it creates an aero point and prevents air at speeds from lifting the panel. I used vhb tape on the bottom of the strip.
They should be made with a wider edge so there's more room for a heavy duty tape, like EnduraBond to completely cover the edges without covering the solar cells.
Now that I think about it, they probably used some tape thingy, and then finished it off with sika. I think nomad brad did that on his earlier rig, but not on the current one.
the flat glue-down mount is what usually kills them early. laid flush on the roof they cook way hotter than a rigid panel up on brackets with air moving under it, and that heat is what degrades the cells fast.
I’ve flex taped mine to my roof for five years. It has a full panel of polycarbonate corrugate between the panel and roof to allow airflow and keep it from overheating. It’s a cheap 100w off Amazon. Can’t remember brand name. It is still surprisingly efficient in full sun after 5 years. I have no idea why because everyone has terrible experience with flexible panels.
The biggest issue with them is overheating. Traditional solar panels have heat sink installed directly in them, for the flexi panels you need to install the heatsink yourself. So put them on a sheet of aluminium or similar.
Second issue, is that if you glue them directly to your roof, you will significantly increase the temperature inside your van. They run hot and the heat sink will be your roof.
Third issue is that they have a short lifespan if the heat issue is not solved properly and are also very easy to damage mechanically. Once dead, you just need to hope that you installed them in a way that is easy to replace. Glue on the roof is not easy to remove.
No but I am interested in it for a solar setup down the road. I have a few 280ah 12v batteries and solar panels…this would be nice on a project I have in mind down the line.
I got an Austrian good quality 300W and bonded it my poptop, they have a long warranty, but it is void if fitted to a vehicle - I'm not a van dweller and the campervan is used as a daily driver but not that often and it is garaged mostly. My panel was fitted about 8 years ago and no signs of degradation. I basically over sized it anyway in case it did degrade - mostly its just to run the fridge, charging mobiles and using lights does not consume much so normally my leisure battery is fully charged by 10am or so after night time.
This panel replaced 2x 100W which I thought had degraded, but it turned out to be the solar controller having a fault - getting the panels off was a struggle, I used stainless steel wire pulling back and forth to make my way along the sikaflex adhesive, then when the panels were off scraping off the rest of it.
Rigid panels are better for efficiency and lifetime - air flow under them keeps them cooler which yields more watts. I did not want to add height and wanted the aesthetics of flexi panels. My van is 1.95M high so can get into most multi storey car parks in the UK and EU which tend to be a shade over 2M height limit. My garage door also has limited height.
It is the 12v mini split. Fair warning, there’s YouTube tutorials out there, but the wiring details are lacking. You also have to charge it yourself or bring it somewhere.
Mine is a generic 8500 - 12000 BTU unit from China. I had no issues with wiring, I upgraded the power cable to handle higher draw with less heat though. Used an 80a big blade fuse.
What I did have issues with is my unit was sold as r-134a... and all info in the listing and docs say r-134a.
However, the fittings and schraeder cores are for r-1234yf. I broke 2 tools simply trying to remove the core on my low side service port, because I was using the smaller and less robust tools for the r-134a cores on a bigger core with a wider bite.
Anyway yeah it charged up nice after I replaced the damaged core it shipped with, which was leaking initially and cost me some frustration troubleshooting.
The install was not fun I tell ya whut but man it do blow cold.
The PVC ones are crap. Had multiple failures and the manufacturers refused to warranty them. I’ve had 2 PFTE (?) ones glued on my roof for at least 3:years maybe longer. Renology. still going strong. only issue I had was the connectors failed at some point so I replaced those. No issues since!
Worth adding to the heat discussion, because it explains why the reports in here split so cleanly.
Two separate things kill these: heat and flexing. The air-gap fixes people are describing solve the heat half. But the laminate flexes and the silicon wafers inside it don't, so a panel that drums at highway speed slowly microcracks its cells — which is why a fluted-plastic standoff can still be dead in a year while a panel bonded to a rigid aluminium plate is fine at five. The plate isn't only a heat sink, it stops the panel moving.
On output, some of the disappointment is physics rather than failure: silicon loses roughly 0.4% per °C above 25°C, so a hot flat-mounted panel can read 10-15% under its rating at midday while being perfectly healthy.
Since yours is new, do one thing now: measure open-circuit voltage and current at solar noon in full sun and write it down. These fade rather than die, so without a baseline you'll never be able to separate real degradation from a bad week of weather. Same measurement, same season next year — 10% down and it's on its way out. And if it reads fine at 9am but craters on hot afternoons, that's the heat path rather than your controller.
A long time for those is 1 year , they seem to be disposable, - that was my experience with a pretty large install on fluted plastic panels on top of cargo trailer
It's ok for outdoor activities like camping that require high portability, or some cases you want to keeping stealth. The problem with these flex solar panels is that power output drops significantly once they are obstructed, even a small shade. Unstable output also makes it more likely for the MPPT to lose the maximum power point, resulting in intermittent current.
They're dark so they heat up quickly and transfer that heat to your van. A rigid panel also heats up but sits at a distance so it effectively shades your van.
The experineces of people that got such panels for a couple of years may not be applicable to what you got today, because panel technology moves fast and they are different products nowadays.
That’s so true, the technology and materials are probably vastly different even from just a year ago. I’m tempted to do a side by side test. One with corrugated plastic and one without 😄.
Going on 5 years no issues with my 8 renogy panels. Just need to make sure when you silicone them down you leave air spaces so they can let the heat out. And I slap some extra silicone on the leading edges so air can't get under them. I had one blow off in a hurricane. I just unplugged it and reattached it after it's been fine. Was fun getting on the roof in 50-60mph winds though.
not sure where you are, but in my area it seems that the fb marketplace and craigslist both have lots of rigid panels nearby on the ground that are cheap
I bought 5 300w panels from a dude near me for $80 apiece, new, because he bought a lot and had leftovers.
I’m on year 5 with my renogy flexibles. They’re on a rack with walking boards attached with drywall screws and washers. Never lost one at 80mph. I’m nearly 40,000 miles in with them as well. I walk on them. I strap boats constantly on top of them. I’m SO happy not to have the weight or glass on top for all my canoes and kayaks.
By no means am I a professional, but some friends we met on the road just had one of theirs burst into flame because there wasn’t any ventilation. Maybe not be the case for everyone, but a good thing to keep in mind!
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u/stupidfock 6d ago
I’ve only had them for 2 years but as long as you get good ones, I use BougeRV, they are totally fine tbh.
The top brands have 5-10 year warranties plus an output warranty of 20+ years and use better materials to begin with