Do Working Solar Panels Run Hotter or Cooler than Disconnected Ones ?

[Mart]

More importantly, which panel is heavier, the one plugged in and moving heavy electrons, or the one just sitting there sagging under the weight of photons building up. I needs to know?

[Bugtownboy]

Ah, but does the flow of electrons in Nowty’s perfectly angled panels generate lift, therefore negating conventional weight measuring equipment ?

[spread-tee]

Oh come on now chaps, everyone knows light is heavy..............

Desp

[nowty]

OK, so maybe Nowty Towers decking area and using a £5 ebay IR thermometer isn't exactly National Physical Laboratory conditions, but I think the result was quite convincing and more so than I was expecting it to be.

The result was 3 (the disconnected panel was hotter), I reckon Tinbum gave the most correct explanation I agree with.

Today was good for this test because we had a mixture of conditions in the middle of the day, some heavy dark cloud, some light cloud and some good spells of full sun.

Test 1 with the 250w Suntechs.
In heavy cloud, (circa 1 amp) it was inconclusive, I could generally measure a fraction a a degree difference but I could not say for certain as there were some inconsistencies.

In bright cloudy conditions, (circa 3 amps), the disconnected panel was consistently 1 degree hotter.

In full sun, (circa 7 amps), the disconnected panel was consistently 2 degrees hotter.

Connected Panel


Disconnected Panel



Test 2 with the 335w Panasonics
When I did this test it was either full sun or full heavy cloud.

First without the plank the temp was the same within 0.1 degree whatever the sun was like.

Then with the plank on the right panel in full sun, that panel was at least 3 degrees hotter. Even when the sun went behind a heavy cloud the temp difference was still there for 10 seconds or so before the temps dropped off and equalised. I even tried the temp underneath the panels and still had similar temp differences. I also did a video panning back and forth between the two panels and the step change is instant as I move from one to the other and back again. My theory on why the Panasonics were a higher difference is they are a more efficient panel. They were also slightly hotter but they had a slightly higher angle and are slightly more southerly facing.


Unshaded Panel


Shaded (with plank) Panel




But just maybe I didn't need to do the experiment as pussy already knew the answer and chose the coolest spot, under the connected Suntech panel.

[Bugtownboy]

And the prize for the correct choice

Nice that Felix can beat physics/measuring technology every time

[nowty]

Worked out how to link the video I was talking about, the temp difference is far more obvious in a video.

Video of Panel Temperature