Air gap on van roof for commercial panel ?

[hertfordnc]

I have one 370 watt commercial panel for my sprinter. Obviously it was not made for this so i'm trying to find the balance between airflow to remove heat and not turning it into a wing.

I'd kinda' like to set it flat against the roof and maybe drill some holes in it.
So what happens if i get it wrong? I understand it's less efficient if it's hot but how much less?

It's more than i was planning to install anyway so i'm less concerned about it less watts than i am about it launching into a minivan

 

[zanydroid]

The voltage and current vs temperature coefficients are published for each panel so the system level performance would be what the resulting temperature will be from the installation.

If your question was about what the performance drop would be at cell temperature X degrees C you can calculate it from those coefficients.

Perhaps there is a rule of thumb for temp rise vs mounting height you can compose into the model.

 

[HRTKD]

Another concern would be that the build up of heat could roast the paint on the van.

I run two 320 watt panels on the top of my RV toy hauler using standard Z brackets. That's at about 13' height. Mine haven't budged. These panels aren't curved like a wing so they are less likely to have uplift.

 

[SamDeleted]

Last ones I installed , I sealed them by the frame straight to the roof with Stixall sealant


Not perfect I know , but they worked just fine for years and years

 

[richard cabesa]

I would say that the output of the panels sealed to the roof vs. raised for air would be pretty hard to measure the difference.

Where I think you could see a noticeable difference easily with an inferred gun pointed at the ceiling. Place a nice big BLACK panel directly on the roof and take a reading of the interior ceiling after an afternoon. Then raise it up three inches a take another reading. Try to replicate conditions. Time of day, hours, etc. Most of my roof is shaded by panels and the unshaded parts are hotter and my roof is not black.

I guess I’m saying that raising the panels helps with less solar gain more than more solar production

 

[iamscottsweeney]

I for one would not mount it flat to the roof. What I did with mine was add a wind deflector at the very front. The panels are a good five inches off the roof.