8-11 volts out of covered solar panel

Thread Starter

spinnaker

Joined Oct 29, 2009
7,835
I have a new 40 watt solar panel that is replacing an old beat up panel for my signage solar lighting project.

I was testing the panel and get the rated voltage + with no load. That is not the issue,

The problem is when I cover the panel both front and back, I am still getting between 8-11V out of the panel. Plus I can see it climbing!

what is going on here? Does the panel have that much capacitance?

It' couldn't be so sensitive that it could still produce a voltage even though covered by thick cardboard could it? ;)
 

Bernard

Joined Aug 7, 2008
5,788
Surprised me also: Normal output is 4 + kW, on overcast rainy day was still producing 1 kW. Also starts producing before sun hits horizon.
 

Thread Starter

spinnaker

Joined Oct 29, 2009
7,835
Is this in sunlight?
Does it still have voltage at night?
Yes it was.

Once the sun went down and I connected it to my panel, it operated more as expected.

In the evening it was measuring around 10V with the load but as soon as I covered the panel the voltage dropped to zero.

Can panels have a capacitance?
 

Kermit2

Joined Feb 5, 2010
4,162
The panels are most efficient at converting visible wavelengths, but will also convert wavelengths not in this range. Your cardboard may be 'see thru' at wavelengths other than the visible spectrum.
 

shortbus

Joined Sep 30, 2009
8,805
Spinnaker, don't mean to hijack your thread, but have been wondering why they don't/can't make a panel that converts ultraviolet or infrared to electric? Even on cloudy days or at night there is still a large amount of that spectrum available.

We now return you to your previous thread. :)
 

Thread Starter

spinnaker

Joined Oct 29, 2009
7,835
Spinnaker, don't mean to hijack your thread, but have been wondering why they don't/can't make a panel that converts ultraviolet or infrared to electric? Even on cloudy days or at night there is still a large amount of that spectrum available.

We now return you to your previous thread. :)
No problem. My guess that it is possible but there is just not enough energy in those wave lengths to make it worth it.
 
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