Solar panels, how high should they be above the roof

[Fisherguy]

Hope to mount my panels this weekend, making brackets out of aluminium angle, how high should they be above the rubber roof? Most commercial brackets seem to have them 1" high, would 2" be better, help with cooling etc with a bit of an angle for water to run off etc?
One panel will be one across the front in front of the skylight, 1 down each side beside the front skylight.
Thanks

[Johnny_G1]

The 4 little bracket's that you get with a panel are all you need to mount a panel, you don't need them sloped to let water run off them, unless you are gonna tilt them 1" off the roof is sufficient. Just my thought's.