Removing solar flexi panel

[Mark and Mindy]

Our 120W solar flexi panel appears to have failed. It is only outputting 10 volts in the hot sunshine but the problem may be due to some thermal expansion factor because on cool overcast days it sometimes outputs 19 volts but no amps.

The supplier is arranging a warranty replacement. I have to remove the old panel in as good a condition as possible so they can understand what the fault is.

I have ordered a windscreen removal cutting wire from Amazon.

Does anyone have experience of removing a solar flexi panel which is bonded to the roof of a Fiat Ducato PVC van and without damaging the roof of the van?

 

[Minxy]

Hmm ... depending on how well you stuck it in the first place it could be easy or hard ... have you tried tightening up all the joints etc to see if it's just an intermittent fault - I found that on one of my panels a connector hadn't been fully tightened when it was made, once done up it was fine.

 

[Mark and Mindy]

I didn't do the sticking because this solar flexipanel was supplied and installed by by the motorhome dealer we purchased our van from so I'm a complete newbie when it comes to fitting and removing.

The panel has a fixed lead that is sealed onto the panel and the other end of the lead is is disconnected from the controller for measuring the open circuit voltage so there are no interconnections.

My big concern is that once I start I've got to finish or our van won't be moving for a while.

 

[Late Starting]

If it’s under warranty get the suppliers or dealer who fitted it to pay or do the job SIMPLES.
CLIFF

 

[Abacist]

If it’s under warranty get the suppliers or dealer who fitted it to pay or do the job SIMPLES.
CLIFF

It may be that only the panel is under warranty in which case the dealer may want to charge for the labour involved if there is nothing wrong with the installation but the panel is at fault.

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[Mark and Mindy]

If it’s under warranty get the suppliers or dealer who fitted it to pay or do the job SIMPLES.
CLIFF

Unfortunately the supplying dealer is two-and-a-half hours drive away and they can't book us in until the 6th of October and it would be a two or three day job so we will have to take two vehicles and days off work for me.

This was vaguely considered when we ordered and took delivery of our van but it's not really much of a concern because for jobs like this I prefer to do the work myself. I can usually do a better job which is more reliable and if it does break it's only down to me and I know what I did and how to fix it anyway.

 

[Emmit]

If the dealer supplied the panel it is of no importance that he did a wonderful job of fitting it.
They are responsible for the replacement. The solar panel has failed and is not 'Fit for purpose'
It is not your job to replace it.

If given the opportunity, have a rigid panel fitted. Anecdotally they are more reliable.

 

[Two on Tour]

I think the windscreen removal cutting wire you have ordered is probably your best bet for removing your duff panel.

I recently fitted a couple of semi flexible panels on our van, but was thinking ahead in case they needed to be removed, plus I wanted ventilation under the panels as they get hot, so I made mounting blocks which I bonded to the roof and then bolted the panels to the mounting blocks.
Might be worth thinking about when you come to fit your replacement panel.

 

[Mark and Mindy]

That looks really neat. Are the blocks to the van roof only bonded and not not screwed? My problem is that the flexipanel is fully bonded to the roof of our van so it is a big area to debond but I'm not sure I would be confident enough to refit and only use bonded blocks.

 

[Two on Tour]

Believe me those blocks are going nowhere, they are bonded to the roof with Sikaflex 292i marine adhesive which is what they glue parts to ocean going racing yachts with.

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[Minxy]

I think the windscreen removal cutting wire you have ordered is probably your best bet for removing your duff panel.

I recently fitted a couple of semi flexible panels on our van, but was thinking ahead in case they needed to be removed, plus I wanted ventilation under the panels as they get hot, so I made mounting blocks which I bonded to the roof and then bolted the panels to the mounting blocks.
Might be worth thinking about when you come to fit your replacement panel.

View attachment 407448

View attachment 407451

View attachment 407449

I have a major concern that those new panels won't last long as they will flex like mad as you drive along and mean the 'cell' connections will likely be subject to a lot of stress/movement for which they weren't intended. They may be semi-flexible panels but that is so that you can 'bend' them to fit a curved surface and then fix securely in place, they are not mean to be 'self supporting' as they will flap around like Rolf Harris' wobble board!

 

[Two on Tour]

I have a major concern that those new panels won't last long as they will flex like mad as you drive along and mean the 'cell' connections will likely be subject to a lot of stress/movement for which they weren't intended. They may be semi-flexible panels but that is so that you can 'bend' them to fit a curved surface and then fix securely in place, they are not mean to be 'self supporting' as they will flap around like Rolf Harris' wobble board!

I have not considered using semi-flexible panels in the past due to their failure rate since they introduction onto the market and seemingly due mainly due as you point out to cell connection failure.
The cause of these failure I believe was as much due to the greater difference in the coefficient of expansion of the semi-flexible panel backing material and the cells bonded to the backing as well as poor jointing of the cell connections and vibration/flexing.
Solar panels both produce heat and absorb heat from the sun, so they are normally mounted with an air gap under them to allow airflow to take some of this heat away.
Bonding semi-flexible panels directly to a surface does not allow cooling air to the back of the panel which then means it gets hotter and the different material expansion rates become greater and this difference in expansion rate plays a part as the panel cools which in turn acts on the cell connections. Another downside is that the hotter a solar panel gets the less efficient it is.

Semi-flexible panels would not of been my first choice, but being borderline weight on our back axle and with no viable space on the roof at the front of the van, the only real option was right at the back end on the overhang which meant adding yet more weight on the back axle.
I bought the panels after a conversation with the supplier in which I asked and he explained that with these panels the backing used was chosen to minimise different material expansion rates and the cell connections were wired so that if a cell connection failed you would only loose a line of cells and not the whole panel and the cells were divided up into multiple lines, also the panel covering was ETFE which is a self cleaning material. The semi-flexible panels I fitted are 80 watt panels and weighed in at 4kg for the pair compared to 13.5 kg for rigid panels.

Having deciding on semi-flexible to save weight, this now threw up the problem of mounting the panels.
Our van roof is of the floating skin type with the aluminium skin being only 0.5mm thick, so I was not comfortable with the prospect of trying to remove a panel bonded direct to the roof skin if the panel failed at some point, plus I wanted airflow under the panels to aid cooling and panel efficiency.
The panels bolted to raised mounts addressed both easy panel removal and air space under the panels.
Since take the photos, I have added an additional mounting block at the centre of each of the panels which is taller than the edge mounting blocks, for two reasons.
Firstly, being just fixed at the edges, the panels naturally drooped in the middle, which allowed water to settle in the middle when parked up. With the taller mounting block at the centre of the panels, the water now runs off the panels, and secondly, the centre mounting block now tensions the panel which should help to reduce the Rolf Harris' wobble board effect.

Time will tell if this was a great idea or a disaster waiting to happen ....................... watch this space.

I'm thinking about mounting one of my action cameras up there to see what's going on with the panels when driving, could make interesting viewing or a horror movie.

 

[Minxy]

I have not considered using semi-flexible panels in the past due to their failure rate since they introduction onto the market and seemingly due mainly due as you point out to cell connection failure.
The cause of these failure I believe was as much due to the greater difference in the coefficient of expansion of the semi-flexible panel backing material and the cells bonded to the backing as well as poor jointing of the cell connections and vibration/flexing.
Solar panels both produce heat and absorb heat from the sun, so they are normally mounted with an air gap under them to allow airflow to take some of this heat away.
Bonding semi-flexible panels directly to a surface does not allow cooling air to the back of the panel which then means it gets hotter and the different material expansion rates become greater and this difference in expansion rate plays a part as the panel cools which in turn acts on the cell connections. Another downside is that the hotter a solar panel gets the less efficient it is.

Semi-flexible panels would not of been my first choice, but being borderline weight on our back axle and with no viable space on the roof at the front of the van, the only real option was right at the back end on the overhang which meant adding yet more weight on the back axle.
I bought the panels after a conversation with the supplier in which I asked and he explained that with these panels the backing used was chosen to minimise different material expansion rates and the cell connections were wired so that if a cell connection failed you would only loose a line of cells and not the whole panel and the cells were divided up into multiple lines, also the panel covering was ETFE which is a self cleaning material. The semi-flexible panels I fitted are 80 watt panels and weighed in at 4kg for the pair compared to 13.5 kg for rigid panels.

Having deciding on semi-flexible to save weight, this now threw up the problem of mounting the panels.
Our van roof is of the floating skin type with the aluminium skin being only 0.5mm thick, so I was not comfortable with the prospect of trying to remove a panel bonded direct to the roof skin if the panel failed at some point, plus I wanted airflow under the panels to aid cooling and panel efficiency.
The panels bolted to raised mounts addressed both easy panel removal and air space under the panels.
Since take the photos, I have added an additional mounting block at the centre of each of the panels which is taller than the edge mounting blocks, for two reasons.
Firstly, being just fixed at the edges, the panels naturally drooped in the middle, which allowed water to settle in the middle when parked up. With the taller mounting block at the centre of the panels, the water now runs off the panels, and secondly, the centre mounting block now tensions the panel which should help to reduce the Rolf Harris' wobble board effect.

Time will tell if this was a great idea or a disaster waiting to happen ....................... watch this space.

I understand your reasoning completely but I would have mounted them on a slim ladder frame to give support which wouldn't add much weight; it would have been very easy to do and if it replaced the upper block the height would have been no more than you have already and also allow the airflow underneath. Also the ladder frame would give some protection if they got hit at the side from a tree limb etc which does happen to the best of us no matter how carefully we drive down some narrow roads. Hopefully the centre block will help with the wobble and water retention (I had notice the 'dip' in them).

I'm thinking about mounting one of my action cameras up there to see what's going on with the panels when driving, could make interesting viewing or a horror movie.

Forget the camera ... stick a 'relation' up there for a 'road surfing' experience!

 

[jockaneezer]

My problem is that the flexipanel is fully bonded to the roof of our van so it is a big area to debond

I'm pretty sure the panel will only be held on by a 10mm wide bead run around the periphery of the panel with a few "blobs" under the middle to stop it flexing. Your windscreen wire will probably be fine.
I removed mine with a sharpened hacksaw blade with tape around the handle, it was a bit of a struggle, wish I'd known about the windscreen wire.
Mind, you could always glue the new one on top of the old one once you've removed that terminal box ?

 

[Mark and Mindy]

Thank you to everyone for your comments and suggestions so far which will be very useful.

Here is a bit of an update.

First of all I can't fault the supplier because I thought that I was still negotiating for them to provide a replacement panel directly to me instead of going though the dealer that fitted it when lo and behold a brand new panel and adhesive was delivered today.

The supplier has comprehensive info on the support page on their website and they do give revised instructions for bonding the panel https://www.solartechnology.co.uk/support-1/pv-logic/flexi-support/ but they also provided me with a recent technical bulletin which does give some cause to concern since it mentions "failure has been a result of separation of an electrical busbar", "caused by the high temperatures", "excessive thermal expansion" and "Temperatures have been breaking records". If we have this problem in the UK then what happens when we take the van to the Spain? These solar flexi panels are a great solution I do feel sorry for them if their product has a problem.

I'm feeling a little more confident about removing the failed panel as what seemed to be so large and unmanageable whilst up on the van roof now seems much smaller and less significant now that I have one in my hands.

I will keep you updated on progress and of course once removed I will have the next dilemma of fitting the new panel and the usual concerns of it flying off whilst we drive up the M1.

Mark

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[Campervan_man]

Start lifting the solar panel at one corner and it should peel off. A hot hair drier { not heat gun } may help if applied to the sealant. Inserted wide wooden wedges will help pry the panel off and shouldn't damage the paint. Do a bit at a time and it will come off.

 

[Mark and Mindy]

I'm working on getting this flexipanel off now and having a nightmare. It's been glued down for the full length on every roof ridge and the good access is only from one side. The windscreen wire (cheese wire) got me started but only went through a few centimetre because you have to work across the whole width of the panel and it actually started sawing into the panel. Best technique at the moment is to push a scraper in from the side millimetre by millimeter.

 

[TheBig1]

go to a pound shop and get a pack of those extending box cutters. Slide the blade right out and with long strokes cut the sealant one rib at a time. If not, a long serrated bread knife works well, but ruins the knife

 

[Mark and Mindy]

Slowly making progress. I have resorted to extreme bending up of the panel and if the sealant seam is exposed then the scraper easily splits it but it is surrounded by skylights on three sides and the difficulty is getting the access and leverage.

 

[Landy Andy]

Long extendable craft knifes, the ones with the wider/stronger 25mm blade, scraper behind to keep the pressure off the blade and lubricant on the blade would be my method

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[Mark and Mindy]

I finally managed to get the the failed solar flexi panel off this evening. A combination of pushing in with a scraper around the edges and then effectively peeling the panel off the roof. Not a pretty sight and I might get reported for solar panel abuse. The adhesive is not Sikaflex as the replacement panel came with Teroson MS939. I removed most of the residue by holding brand new Stanley blade in pliers and gently slicing down the roof ridges. I've cleaned up one roof ridge and it's looking good.

A pristine brand new solar panel is a joy to behold and offering so much potential for free clean energy but a busted half removed bent out of shape solar panel is a very sad sight

 

[DBK]

Is the problem with a flexible panel on a PVC roof is it is unsupported between the ridges? I would have thought they were only suitable for smooth surfaces, either flat or curved, which can fully support them.

 

[Two on Tour]

I always use ScrewFix silicone remover, may take a few applications and a bit of time, but it will not damage your paintwork as a blade is likely to do and having tried various of the big name versions, believe me the ScrewFix one is the best, read a few of the reviews on it.

https://www.screwfix.com/p/no-nonsense-sealant-remover-100ml/88987

 

[Mark and Mindy]

Is the problem with a flexible panel on a PVC roof is it is unsupported between the ridges? I would have thought they were only suitable for smooth surfaces, either flat or curved, which can fully support them.

I uploaded the manufacturers technical bulletin in an earlier post which specifically mentions how to deal with a ribbed roof.

 

[Mark and Mindy]

I always use ScrewFix silicone remover, may take a few applications and a bit of time, but it will not damage your paintwork as a blade is likely to do and having tried various of the big name versions, believe me the ScrewFix one is the best, read a few of the reviews on it.

https://www.screwfix.com/p/no-nonsense-sealant-remover-100ml/88987

There many factors to consider and not least that I had to push in a scraper around the edges. I have got some Screwfix silicone remover and I will give it a try but I think this is PU adhesive and not silicone.

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[jockaneezer]

Now sell the replacement one on eBay and put the money towards buying yourself a rigid one to go on your van cos you will end up taking the new flexible off again ! BTGTTS

 

[cmcardle75]

I gave up on semi-flex. They only last a year before all the cells disconnect from each other.

 

[Mark and Mindy]

Now sell the replacement one on eBay and put the money towards buying yourself a rigid one to go on your van cos you will end up taking the new flexible off again ! BTGTTS

For the long-term I have some ideas for changing to rigid solar panels but for now I will have to continue with the semi flexible solar panel. At least whennit has to come off next time should be a little easier.

 

[Minxy]

a busted half removed bent out of shape solar panel is a very sad sight ☹

View attachment 408545

Reminds me of a stingray!

 

[Grainfoot]

Reminds me of a stingray!

For the long-term I have some ideas for changing to rigid solar panels but for now I will have to continue with the semi flexible solar panel. At least whennit has to come off next time should be a little easier.

How did you get on with new panel in the end. Did the solvent work for cleaning old panel off.
We have same problem. A replacement is being sent but we have to replace.

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