Optimal height above the roof for solar panels

[Sandpiper]

What is the optimal height above the roof for solar panel placement?
I would like to have the maximum coverage of my Promaster 1500 136 hightop roof with solar panel to shade the roof and generate the maximum power while running 2 Maxair fans.
There seem to be a trade off between having the fans running (need 9 inch clearance while fully opened) under the panel and the wind resistance  because of the the increased height above the roof.
If I use 2 305 Watt panels I can get 2 panels and two fans without high wind resistance, but if I add a third panel, the panels must be 10 inches above the the roof so the fans can be fully open when needed.

Another option is to have a panel placed above another panel and slide out so both have sun access while parked. In this way I could have 4 panels and still have a lower profile.

Anyone done this? All comments are welcome!

 

[WalkaboutTed]

Why not both? We have the two 180 watt panels on the roof rack in front of the fan. And the van has a side panel to catch the morning sun If it's needed. Usually not though, even though we daily use the fridge, microwave, coffee maker and hot pot for my tea. Today we took in well over a kilowatt.

Ted

 

[maki2]

What is the optimal height above the roof for solar panel placement?
I would like to have the maximum coverage of my Promaster 1500 136 hightop roof with solar panel to shade the roof and generate the maximum power while running 2 Maxair fans.
There seem to be a trade off between having the fans running (need 9 inch clearance while fully opened) under the panel and the wind resistance  because of the the increased height above the roof.
If I use 2 305 Watt panels I can get 2 panels and two fans without high wind resistance, but if I add a third panel, the panels must be 10 inches above the the roof so the fans can be fully open when needed.

Another option is to have a panel placed above another panel and slide out so both have sun access while parked. In this way I could have 4 panels and still have a lower profile.

Anyone done this? All comments are welcome!

The optimal height is not that difficult to estimate. You can do that by looking at the dimensions of the brackets they sell for mounting the panels.  An alternate is to cover the main area of the roof with panels of matching size and put all on those on one controller. Then use smaller sized panels on each side of the roof vent and put them on their own controller. Both controllers feed into the battery charger. I would suggest you do a consultation with the solar panel companies you plan to purchase the panels from, that won't cost you anything. But first make a sketch of your roof area with the relevant dimensions of space and location of the vent. Then scan or take a photo of it or create it as a file type that you can send in email to the person who is advising you.