Flexible Solar Panels, any bought off ebay?

[hairydog]

I have both a stuck-on flexy panel and some rigid panels with air behind them. The flexy dissipates best to the air above and the roof below. It is no warmer than the others in actual use, possibly cooler. The space below a solar panel is looking me a greenhouse and gets very hot
.
The people who suggest needing an air space don't seem to have actual experience of them.

I would suggest that if you want them to last, you need to mount them so they are very rigidly held. Any arrangement that allows even slight movement will shorten their life dramatically. They need to be stuck down to the roof.

 

[Owlhouse]

I have both a stuck-on flexy panel and some rigid panels with air behind them. The flexy dissipates best to the air above and the roof below. It is no warmer than the others in actual use, possibly cooler. The space below a solar panel is looking me a greenhouse and gets very hot
.
The people who suggest needing an air space don't seem to have actual experience of them.

I would suggest that if you want them to last, you need to mount them so they are very rigidly held. Any arrangement that allows even slight movement will shorten their life dramatically. They need to be stuck down to the roof.

With respect to your experience, mine is that having the roof as a heat sink may be fine in the UK but go to warmer climes and they get very hot, the roof cannot dissipate the heat, heat is the biggest killer of solar panels.

 

[maja07]

Hot climes

I will need a setup that will survive in southern Spain...well over winter I mean...can still be hot in direct sunlight. Maja

 

[hairydog]

With respect to your experience, mine is that having the roof as a heat sink may be fine in the UK but go to warmer climes and they get very hot, the roof cannot dissipate the heat, heat is the biggest killer of solar panels.

Sorry, but that is definitely not true. When it comes to semi-flexible solar panels, movement is a vastly bigger killer. Flex the panel repeatedly and it will fail.

The voltage output of a solar panel does drop as it gets hot. It goes down by up to 0.6% per degree over the standard temperature of 25 degrees C.

I think the maximum operating temperature is around 85 degrees celcius (by then the output will have dropped by about 30%). I don't think you will get a panel that hot in Europe.

 

[maja07]

Both ways

Hi folks, maybe a silly question but do the panels flex both ways ? I would like to install panels on section of roof that would require them to flex slightly the other way that you see on eBay etc. Maja

 

[hairydog]

Hi folks, maybe a silly question but do the panels flex both ways ? I would like to install panels on section of roof that would require them to flex slightly the other way that you see on eBay etc. Maja

No. Imagine you were fitting a sheet of very thin hardboard. To flex two ways it would have to stretch as well as bend.

 

[maja07]

....hmmm I just mean can you bend them slightly inwards ?

 

[maja07]

Weight

.....actually, might go for the rigids as not fussed about a few extra kg on roof....