A few years back I bought some solar panels at a Hamfest. I was disappointed to find out that they are only 10 watts each. By todays standards that is very little power per square foot. I also bought a solar battery charged on eBay to connect the solar panels up to a battery.
Here is what my very basic setup looks like. I do not have any "Load" connected yet but I do have an inverter to convert 12 volts to 120 VAC. The charger has two USB jacks to charge your cell phone.
This year I decided to update the solar panels to some higher power versions. I bought two 50 Watt panels on eBay for under $60. This picture is of the ad that appeared on eBay.
This is the accessories bag that came with the panels. There is a device to plug into a cigarette lighter to charge a car battery and clips to clip directly onto a battery. Then there are four suction cups that I suppose is how you are supposed to mount the panels.
This picture shows how two of the new 50 watt panels can fit on one of the old 10 watt panels. That should take me from 10 Watts to 100 Watts per three square feet. However, I would not recommend this type of mounting as the suction cups repeatedly failed when trying to take this picture.
I am thinking I will need to make a frame out of wood or metal and then mount the new panels on the frame. Then the frame could be mounted to the roof.