Hi.
am thinking of replacing my (heavy) 80w folding panel with 100W semi flexible one (2.5 kilos). I want to fix it on the caravan roof using the supplied 6 brackets which have bespoke bolts and the panel has 6 ringed holes on its perimeter. Does anyone have experience of the semi flexible panel fitted in this way? I know they are extensively used on boats.
any comments appreciated
thanks
Only in the narrow boat world, and people have found a problem with them overheating, producing poor output and failing quickly.
A "hard" panel is cooler because it has an air gap below.
I agree with LlaniDavid regarding the heat issue, and wouldn't bother with a flexible panel. I have read also of a higher failure rate with these panels.
I fitted a 100watt panel to the roof of my former Bailey van and fitted it with the stand-off feet that provide good airflow around the panel, plus you bond the feet to the roof as opposed to having to drill for fixings to the roof.
There are arguments fore and against roof fitting (mainly reduced efficiency due to angle of panel), but for me the convenience outweighed the performance, which in fact was more than satisfactory for my needs.
The panels that have a peelable backing so they stick direct to the roof are quiet good as the caravan roof is a good heatsink, I would avoid the other type.
Flexible panels have ben in use for over 10 years and do not have a higher failure rate than other types of panel. This is an old wives take put about by those who know nothing about the subject. Do you think so many manufacturers would produce them if they kept having to replace them?
My local caravan dealer has installed "hundreds" and not yet had any back. My caravan one is 2 years old and my narrow boat has had one on for over 5 years. I personally have had no issues whatsoever.
They are much lighter than conventional panels and need only to the "stuck" down on the roof with Silkoflex. If you did get a bad one all you do is stick another one on top. Additionally they cannot be damaged by a falling branch, hail etc (or an errant football) and you can even walk on them as there is no glass to break. No brainer really on a caravan or boat.
Thanks for your comments.interesting to hear arguments both ways! I take onboard the sun angle argument particularly if winter caravanning when the sun has a southerly declination (obtuse angle to the SP).I think it is worth the gamble given the convenience of use and relative inexpensive cost.May have to double up the SP watts !!
I have had a narrow boat for 20 years and I disagree with LD. I have these panels, does LD or is he just repeating what he is read?
Noticed the Yorkshire girls who rowed across the Atlantic had flexible panels.
Good luck whatever you choose. They are well worthwhile. Personally I have found a fixed roof panel of 100w. Works well and no need to mess about with it Also it's not going to be stolen.
I have 2 semi flex panels. One 50 watt and aluminium backed that is OK after 27 months.
Another 100 watt and plastic backed. Purchased from RENYTEK via Ebay It has degraded by 50% after 13 months. Renytek have been singularly unhelpful apart from asking me if I wished to purchase another similar panel !! I declined their offer in no uncertain terms. Its a bit pot luck but I would at least avoid RENYTEK.
Quote: Originally posted by Paul_B on 28/3/2016
The panels that have a peelable backing so they stick direct to the roof are quiet good as the caravan roof is a good heatsink, I would avoid the other type.
Paul
The caravan roof even if skinned in aluminium is not going to be a good heat sink, as it has hopefully some good thermal insulation under the skin. The aluminium will pick up the heat readily but the insulation give it nowhere then to dump it, so its temperature will rise and with it derate the panel.
However, I would expect the panels to be rated for applications where direct heat transfer is not going to be good.
Like Fysherman, I found the 100w panel provided enough output for our needs all year round, although we've never been 'demanding' users, eg infrequent TV, LED lighting etc.
To be fair, the info I had on flex panels was from a few years ago, as I researched them as an option to rigid panels at the time. I happen to live in close proximity to a large canal network and having spoken with a good number of folk on the water (living in, not 'boating tourists'), the general consensus was that the flexible panels had been problematic, with a few users having switched to the rigid panels. My brother also operates a boat from Lymington and again I found poor feedback from users there too. Maybe they had tried 'inferior' brands, but for whatever reasons, my opinion at the time was they weren't worth the bother.
Whichever way you go and despite the inefficiencies, the fixed panel offers (IMO) more pro's than con's.
Quote: Originally posted by Paul_B on 28/3/2016
The panels that have a peelable backing so they stick direct to the roof are quiet good as the caravan roof is a good heatsink, I would avoid the other type.
Paul
The caravan roof even if skinned in aluminium is not going to be a good heat sink, as it has hopefully some good thermal insulation under the skin. The aluminium will pick up the heat readily but the insulation give it nowhere then to dump it, so its temperature will rise and with it derate the panel.
However, I would expect the panels to be rated for applications where direct heat transfer is not going to be good.
I really meant an aluminum roof, an aluminium roof is an excellent heat sink, the insulation isn't a problem as the roof has a very large area where it can disperse the heat.
Easily checked by testing the temperature on a standard panel against the temperature of a caravan roof panel
I really meant an aluminum roof, an aluminium roof is an excellent heat sink, the insulation isn't a problem as the roof has a very large area where it can disperse the heat.
Easily checked by testing the temperature on a standard panel against the temperature of a caravan roof panel
Whilst aluminium is a good heat sink, a film of rarely more than 0.3 mm thick will not be able to transmit much energy away.
But as said these panels must be designed to achieve their rating when mounted on poor conducting surfaces.
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Topic: semi flexible solar panels
