Possible? Thermal Shade Effect? Panels On Roof?

Yes. I have 10kw on the stick and brick roof. It is *almost* as good as a tree. Figure the panels absorb all the heat from the sun, and radiate 50% back up, the other 50% down into the roof (less convective losses). Even with the ping pong of reradiated heat between the roof and underside of the panels there is still less heat baking the insulation then before. A decent tree will be 4-5 times better at cooling, as there is no real radiation of heat from it to the roof, just OAT's.

My fiberglass roof is white and thin.

I added 1/2 inch foamboard insulation between the osb ribs where the panels reside.

The framed panel averages over an inch distance above the curved roof.

I have a unisolar 68 watt stick on on the other side of the roof.

I never recorded the data but there are large noticeable differences according to my IR gun when aimed at the shadowed portion, the portion in unobstructed sunlight, and then directly under the adhered unisolar panel.

The heat under the unisolar can be felt with ones hand, but it is not enough to melt my surfboard's wax which is strapped to the ceiling wax up.

My roof exhaust is fairly capable too.

Hi,

Basically my panels shade about 25% of my roof. Other shade is provided by the A/C unit, 1 square foot per Maxx Air cover, and the antenna also shades about 1 square foot.

So I guess you could say that about 30% less sunshine is hitting my roof than before installing the solar panels, maxx air covers, and of course the A/C unit reflects heat as well.

I did put some Reflex insulation on my roof while working in Phoenix AZ one summer, and it did help a little. Not to much, so when wind blew it off the roof, I never put it back up. It was about 115 most days, and my 13,500 Btu A/C could only keep it down to about 95 inside on the hot days, while I was at work. After sunset, it would go below 80.

30' Bounder without a slide, with dual pane windows. So fairly good roof insulation, and 1.5" in the sidewalls, and between the basement and floor.

It is something that you could spend a hour calculating how much shade you will have, however I am not that bored.

Have fun camping!

Fred.

Hi,

No.