An often-overlooked consideration is the style and cost of mounts. Most of the "standard" solar kits offered for retail come with what is called a "Flat" mount. These are very inexpensive mounts that bolt directly to the backside of the panel frame and hold the panel flat against the roof.
This type of mount is fine if you have a flat roof and never plan to take advantage of the increased output gained from tilting the panels towards the sun during the winter. However, if your roof is rounded, you will come to despise this type of mount because it just won't work very well for you. You'll have to improvise or buy some other, more expensive mounts.
Also, when it comes time to add another panel, troubleshoot the wiring, or simply to clean the roof, you will be forced to completely remove the panel and mount from your roof in order to access the wire and junction box which are located on the back of the panel. This takes a lot of unnecessary labor, which will cost you money if you are paying someone else to do it; or, time and frustration if you do it yourself. Plus, every time you remove and re-insert a screw, it has a little less holding power and may eventually cause a leak.
If you want to have the option of tilting your panels (for better winter production), you will have to give up the flat mounts and opt for a set of tilt mounts. Most of these mounts are still intended for flat roofs and will require custom modification if your roof is rounded.
There is a Better Way!
After spending many years trying to force those "off the shelf" flat mounts to work on RV roofs, we came up with Rocker Feet, a much simpler and less expensive way to meet nearly every mounting situation we have encountered.
Rocker Feet are made from laser-cut, stainless steel. Unlike aluminum mounts, there are no dangerous sharp edges and your hands won't turn grey when you handle them. These mounts conform to any roof shape, allow easy access to the back of the solar panel for troubleshooting/cleaning, and will allow you to tilt your panels with the addition of inexpensive tilt bars.
Because of the unique design of our Rocker Feet, we had to design an adapter that places embedded nuts on the ENDS of the frame (instead of utilizing the bolt holes on the back of the frame).
Having embedded nuts on the ends of the frame allows the Rocker Feet to swivel and conform to any roof shape and attach with a single bolt (or UV resistant Knob) and a lock washer. This configuration also enables you to easily "flip" the panel over for easy cleaning and access to the wire harness. Experience has taught us that this simple design makes for easy maintenance, and saves you from a lot of frustration!
In order to tilt your panels, simply remove two bolts (the black knobs), tilt the panel up, insert the optional tilt bars and bolt them in place. The design is simple, effective and inexpensive.
Why didn't anyone think of this before? Most likely because all other solar electric systems are designed to work for the broadest range of applications, with RVs being a tiny portion of the market. Our SunRunnerTM Systems are designed specifically for RVs!
Fiberglass roofs – We have been using a type of 3M double-sided tape on our mounts since the mid 1990’s, and we have never lost a panel. As long as the tape is properly installed on a clean surface at the correct temperature, it will hold. As an added level of protection, we use a layer of Dicor self-leveling sealant around the entire perimeter of the mount, and cover the screw holes/heads as well. The sealant protects the tape and any potential roof penetrations from water intrusion and decay.
Rubber Roofs – Along with the 3M double-sided tape, we also include stainless steel ¾” sheet metal screws in the Rocker Foot Mount Set. While the 3M tape will hold to your rubber roof, your rubber roof may not stay attached to the plywood it is bonded to. The sheet metal screws will penetrate through the rubber, into the plywood, to keep your rubber roof from separating while the wind force of highway speed driving pulls at your panels. Again, we bury the entire mounting feet with Dicor self-leveling sealant for weather resistance. Some customers use the screws for an added layer of protection on fiberglass roofs, but we haven’t found that to be necessary.
If you need to temporarily remove your panel for maintenance, you can quickly unscrew the four corner “T” knobs leaving the four mounting feet attached to your roof. In order to remove the mounting feet, pour a pool of isopropyl 91% alcohol behind each foot. Use a putty knife to push the alcohol under the foot. It will be helpful to apply a little sideways pressure to the foot in order to get your putty knife underneath it. Eventually, the foot will cleanly pop off. If you choose to reinstall your panel on another surface you will want to buy a new foot, with a new strip of 3M double-sided tape.
For additional information on AM Solar Rocker Foot Mount Sets, check out these videos: