I just want to add some actual experience info, lowering the roof as a method to tilt your solar panels. I spent 3 weeks in the Big Bend area during the end of January, which is pretty far south, so those up north may not experience the same type of result. I have two Renogy 100 watt solar panels on the roof of my FWC Hawk. On this trip I made a point of always facing my truck south. When I woke up in the morning I would flatten out the bedcovers and then drop the front section of the roof. I was still able to move around and do everything in the camper. I'm 5'8" tall.
Here's what I learned, using the amp meter on my solar controller. Early morning, with the sun in the east, I saw a 0.5 amp gain, immediately dropping the roof. As the sun moved across the sky it would quickly increase to 1.0 and and then by mid day it would max out at about 2.0 amp gain. I took a rest day, hung around camp and read, while checking the readings. As the day progressed and the sun moved westward the amp gain would decrease just as it increased in the morning.
If I drove to a trail head, I would also try to park facing south if possible and raise the rear of the roof before heading out on the trail. There was a side benefit to raising the rear of the roof before hiking, that being, when finished hiking I was able to grab a beer very quickly, since my top loading refrigerator is mounted in the rear of the camper.
Anyway, I thought it was worthwhile tilting the roof.
The other issue I found significant was cleaning my panels. I did lots of driving on dusty roads and my panels would get covered with a thin layer of fine dust. I brought along a telescoping pole with a wash mitt on it. Dusting off my panels, gave me a 0.5 amp gain mid day. There was still a slight film but I didn't have a ladder to really wash the panels, so I can't speak to that.
But why does dust blow onto the panels on dusty roads, but won't blow off when driving on pavement no matter how fast I drive?????
