I can only tell what I have done, what I do and describe my system. I have 4 150 watt panels permanently mounted--no swivels- on my roof and room for at 3 more. I mounted them solid because I do not want to cclimb on the roof just for the extra 10-15% uotput. I have a 3 stage charger,4 225 amp-hour 6 volt batteries and a 1500 watt pure sine wave inverter. iI the summer in Montana, we did not hook up or run a generator for over a month. We watched TV, used 2 laptops, and used the microwave for short periods-less than 5 minutes just to warm something up, plus all the normal stuff--lights (non-LED), water pump and parasitic drain. This winter, the system could not keep up with demand, so we hooked up when possible. I think that if I had put up the other 3 panels that i have room for, it would work in the winter. So, when people tell you that you can not power a RV with only solar power, they are correct. You can not run air conditioners, electric heaters, or other long running heavy draw items. You have to choose where you park, with shade in mind. You need to keep power use in line with your system. And, in the winter, because of less sunlight, you might need to hook up oor run a generator once a week or so to keep a good charge (12.5+ volts) in your batteries. We have been using this system for only 8 months or so. If I had it to do over, I would put in 3 more panels. The reason I haven't is because I built the system when I was still working and drawing social security and had money available. Now that I have retired, I do not have the spare cash to buy the panels and upgrade the charger. The system has given us oppourtunites to boondock for extended periods, but we still need to hookup and go empty the holding tanks and get water.