Flexible solar panels

Good morning

Has anyone tried to fit a solar panel to the curved luton roof of a Nuevo?   This is the only available space due to aerial, sat dish, vents etc.

Sparky

Not a Nuevo but a pal of mine fitted them to his Landrover before a trip to Russia and he said they were great.

I dont think you would be able to fit to a double profile, only single.

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Just in the process of completing my installation on a 2012 Nuevo. I'll put up some more photos when complete, but very, very pleased with it so far. The panel is 100w, less than 2Kg, 1100x540x2mm and £129. It is one of the latest "back connection", technology panels which are more efficient, certainly better than the 3.6Kg, 30 watt standard installation it replaced.

Hi Ploop, who is the supplier as that does look the business ? 

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You will also need some Sikaflex 512, suitable lengths of 4mm solar grade cable and mc4 connectors, 2 Way Feed Gland/Solar Panel.

I'll put together a post on the finer points of my installation over the weekend, as I also modified the EC328 control box and added a remote meter to watch the free electricity arrive!

That really looks good and as you say by replacing existing 30watt panel also saves weight. Looks like I can remove the 30 watt and just connect straight on the the existing wiring. 
Most of our MHing is on non electric sites and with just the 30w we manage for quite a few days without running the engine so this will be just the job me thinks. 

The specs of that panel may explain the apparent discrepancy between power levels and current that have been mentioned in other solar panel threads.
Max voltage is 17.82 V and max current is 5.62A  - Short circuit current is 6.35A.

If the panel can only supply 6.35A when short circuited that implies somewhere between 5.62A and 6.35A when delivering the 13.6V to 14.4V that the Sargent will pass out to the battery when charging.  That sounds like somewhere around 80W effective maximum rather than the theoretical 100W which is 5.62A at 17.82V (5.62 x 17.82 = 100) which cannot be achieved as you cannot pass 17.82V to the batteries.

Or can some solar panel genius correct my calculations?  I have no idea what the panel characteristics are when taking lower voltage. In a domestic installation the inverter takes whatever voltage the panels can put out and then puts out 240V AC.

Nothing wrong with your calculations, that is how solar power ratings are calculated. Its got very little to do with the voltage output from the controller, so this is a good measure for comparing one panel against another. Bare in mind also apart from these panels being flexible, the back connections make them a lot more efficient than the panels with the "lines" on the front. What this means in practice is a physically smaller panel will produce the same amount of power as a bigger, standard one.

Just for comparison this is the spec label on the rear of the "greenhouse" framed panel that was replaced.

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That is the same, proportionately. Likely power at around 14V is about 23W.
I was not criticising your new panel - merely saying that rated power outputs seem to be over optimistic for the actual application environment. Or am I talking a load of rubbish?

No that is just the way all solar panels are rated, even grid tie domestic ones. Power in Watts equals the product of max volts and max current. Find the specs for a 250 watt domestic panel and it follow the same rules, only difference is you're  likely to be looking at twice as many volts. I wouldn't get too bogged down in this, because in reality this is just one of the factors stopping you getting the stated output. Others include mounting the panel flat, using it other than at the equator at mid day, cloud cover, cleanliness of the panel, length of cable runs, resistance at connections, you get the idea. Really all that matters is comparing my two, old and new, the new one is half the weight and produces theee and a bit more times the power of the old one! It is what it is? Hope this helps?

Thanks for th eclarification that I was not talking rubbish.  I raised the issue because there have been threads here before where, for example, the user of a 130W solar panel was worried that they would overload their Sargent controller and Peter Brown commented that the maximum current that he had expereinced from a solar panel was enormously less than its rated wattage divided by 12 - which is what the user was concerned about.

Having said that - it would be interesting to know on what basis Sargent base their recommendation of a maximum solar panel power of 100W for the EC325/8 series.  Presumably they will take into account the sort of things that we have discussed here.