If you can sort out the semi flexible panel grid separation from the modules due to heat, you will be on a winner no matter how much solar you can fit on the awning. I've been trying to sort this problem for 3 yrs and have come up with no real answer besides the way semi flexible solar panels are made leads to this problem. Rigid panels have the module laid first, then the grid soldered to it, semi flexible panels have the grid laid first, then the module placed on op of that. I think this limits the ability to make a secure contact by soldering the joints and the process of applying the cover solution allows some of this solution to make its way between the module and the grid. Heat causing uneven expansion finally separates a module from the grid and with no module bypass in place, the continuity from the panel negative to panel positive is lost.
Hard enough replacing failed roof mounted panels, I can't imagine how hard it would be to replace awning sewn in panels.

T1 Terry

Interesting, hopefully they are a lot further ahead now than when they talked about using the royal mint presses to print solar panels. It was so long ago I thought they must have canned the idea. Then there was solar paint, solar roof tiles ... the list goes on and on. What was never explained was how the interaction between the different layers was linked into either positive or negative output/input so each module could be series linked to build a useful voltage without the current backflow destroying the weakest elements in the series string when there was an output open circuit. They worked under controlled conditions, small scale in the lab, but they never survived scaling up to commercial sized panels along with the mass production give or take half a brick tolerances.

The semi-flexible panels on the market at the moment use a very low loss diode type gate to stop any current backflow, but that is part of the cause of the failures. When an RV solar array charges an RV battery, there is no dump load involved, the solar array just gets switched open circuit, the open circuit voltage becomes so high it can push back through these weakened low loss gates creating a current path. The whole solar array potential current, multiplied by the maximum voltage it can produce that current at, if fed into this module in a virtual short circuit turning it into a heater. There are photos on another thread of thermal imaging showing the actually happening and a few photos of the result. In the semi flexible panels it simply destroys the already poor link between one of the modules and the grid within the panel. At this point there is no longer a circuit within that panel so the next weakest panel suffers the same fate.

Usually there will be 2 or 3 panels still functioning, they were the strongest and between them they can not create enough current at a high enough voltage to push through the gate and destroy the connection.

Fitting blocking diodes really helps, but it also adds a loss as the current passes through each blocking diode, the result, a less efficient panel and in a series string, the losses compound.

As far as useful solar array capacity to meet tomorrow's demands that is actually here now would be around the 1kW minimum. That can be a combination of roof mounted and deployable panels either as part of a roll out awning or even fold out window shades. The greater the capacity the greater the output in less than perfect solar conditions. Very rare to have a cloud free cool day with the sun passing directly over the panels, so what would theoretically be plenty of solar needs to be doubled or even tripled to suit winter down south travelling or mid summer top end travelling when it is really hot yet overcast.

 

T1 Terry 

 

T1 Terry

Craig1 wrote:

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Dont forget the constant expansion and contraction of current awning material, also the way they flex almost constantly with wind.

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Yes, the strain across the material when the get that whip up tears quality awning material, it would be a real test for flexible solar panel material.

Great if it can be achieved, the market will be huge. A gazebo using this type of cover would double as a shade house for eating and relaxing while the RV was parked in the shade, no risk of portable solar panels being stolen or the need to constantly move them because of the area involved and each face getting sun exposure as the sun travelled east/west throughout the day ... well the planet turned but you know what I mean :lol:

Great for those that travel in camper trailers and perfect for the revival of travelling in a Kombi Camper type vehicle. We parked our '74 Kombi under a fold out gazebo thing and that gave us an awning area as well and created a fly sheet type shade to keep the Kombi cool in summer and warm in winter, yet we could drop down the pop up roof and drive out leaving the whole thing still set up, then park back in after our site seeing/town trip.

 

T1 Terry  

Hey Jyothi,

is this associated to the Newcastle Uni?
I thought I heard on the radio about some new tech coming out for solar, similar to what you have described above.
It was a while ago now, so I may be off with the Newcastle bit.

Like others above, happy to help with info etc on my set up.

I think you will find most on here helpful and encouraging when it comes to anything that can be attached to a van :)
Especially when it comes to powering them.

Good luck with it and let us know what you need .


cheers Brett

The awning I have on the side of the car, although nice to have & works well, we barely use it.

If one can make light weight awning solar fabric, then I would assume that this light weight awning material could then be used on the roof. As it would need to be lighter than a flexible panel as an awning or the awning structure will need to be made a lot heavier.

Whenarewethere wrote:

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The awning I have on the side of the car, although nice to have & works well, we barely use it.

If one can make light weight awning solar fabric, then I would assume that this light weight awning material could then be used on the roof. As it would need to be lighter than a flexible panel as an awning or the awning structure will need to be made a lot heavier.

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I think cooling might be a serious issue if you stretched the panel/sheet directly over the roof of the RV. As a flysheet would be a different story, not only keeping the RV cool and dry, it could harvest available sun and act as a summer roof, yet be rolled up and put away when travelling. A few design bits to sort, like how do you support the centre of the solar/summer roof, but maybe the method Aldi used for their curved awning for caravans and smaller RV's, fibreglass rods that connected into each other with a locating pouch each end and a tie affair along the length to hold the rods in place, or even a sleeve for them to slide into .... just lateral thinking here, no idea how practical it would be in operation

 

T1 Terry  

Hi Ge, yes the awning would need to be rolled out for this technology to work. 

My thoughts would be to have the flexible panel separate from the awning, I say that because the awning is usually sloped, but may not be in the direction of the sun, we do not always have a choice. But to have a panel say 2.4 x 1 meter, with a sewn in rope to slide through a sail track, installing sail track on all 4 points of the van and ute canopy. Then it can be set up in the ideal direction to the sun, is not such a big wind sail i.e. can cope with wind gusts and can be left up without a worry.
I have already looked into this, but the opinions of this forum suggested present flex panels did not cope with this arrangement.

travelyounger wrote:

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could you try and get a solar panel that works off the moon that would be great

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Ahhhh, the magical Lunar panels :lol: I have actually seen a few amps from a super moon on my 1600w solar array, but I see more parked under Mercury vapour lights on the highway. Truck trailer exchange parks had them at one stage, they have swapped out to LED in a lot of them, much brighter and no solar charging from those buggas

 

T1 Terry