Solar panel

[Diane1969]

morning, can anyone tell me if there is a way of finding out how many watts a solar panel is that's already fitted? Probably a very daft question but hey I'm new to all this !

 

[ivorantony]

some have the figure printed were the wire comes out but I would try and contact the previous owner and get more information,
solar panels are getting smaller for the same output from the earlier types so measuring will only give you a rough idea,

 

[funflair]

If its written on it will be on the back and you cant see it, measure it and compare to the size and wattage of ones for sale.

Martin

oops too slow, but our old and new 80 watts are near enough the same size.

 

[Diane1969]

some have the figure printed were the wire comes out but I would try and contact the previous owner and get more information,
solar panels are getting smaller for the same output from the earlier types so measuring will only give you a rough idea,

The only thing we could find was a serial number , but I will check again. I had thought about contacting previous owner too

 

[Bacchus]

I would be tempted to try and measure it...

use it to charge a discharged battery, and measure the increase in SoC over a couple of hours on a sunny day and on a cloudy day, you'll get a much better idea of its usefulness than any (often optimistically) quoted output.

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[RowleyBirkinQC]

I had the same question a while ago, before I then found an associated invoice in the folder which told all. I think someone suggested getting a mirror, slide under the (fitted) panel near the wires/terminal, and you may see the wattage stamp in said mirror (or something like that).

Edit: here it is - http://www.motorhomefun.co.uk/forum/threads/solar-panel-how-many-watts-is-it.103133/#post-1319759

 

[Diane1969]

I had the same question a while ago, before I then found an associated invoice in the folder which told all. I think someone suggested getting a mirror, slide under the (fitted) panel near the wires/terminal, and you may see the wattage stamp in said mirror (or something like that).

Edit: here it is - http://www.motorhomefun.co.uk/forum/threads/solar-panel-how-many-watts-is-it.103133/#post-1319759

Thanks interesting read, very informative

 

[Diane1969]

I would be tempted to try and measure it...

use it to charge a discharged battery, and measure the increase in SoC over a couple of hours on a sunny day and on a cloudy day, you'll get a much better idea of its usefulness than any (often optimistically) quoted output.

We will do this when we get it, do they need the strong heat from the sun or is it the brightness on a nice day ? Just thinking the time of year

 

[Bacchus]

We will do this when we get it, do they need the strong heat from the sun or is it the brightness on a nice day ? Just thinking the time of year

PV should depend on "brightness" not "heat" - in theory a bright winter's day should generate the same electricity as a bright summer's day - more in fact because summer days tend to be more hazy.

Of course most winter's days tend to be grey and overcast in the UK (although the coming winter is forecast to be dry and cold because of the El Nino), but measuring it on a grey day would give you information that is just as, if not more useful than measuring its maximum output. I can pretty much guarantee that it will spend more time working on grey days in the UK...

 

[funflair]

As said it is the brightness of the sun but if the panel is flat on the roof it won't generate the same in the winter as the sun is too low compared to summer, panels work best pointed at the sun.

Martin