Re: Solar panel, power gathering experiences
My system has performed as expected for nearly three years, all original parts, no problems or faults at all. Unless there is shade of some kind, I can live off-grid for as long as needed. I added a wind turbine, and it worked as expected, but it's not really necessary.
Available power, via sunshine, is predictable for the most part. The amount of sun-hours per day is known for most of the U.S....multiply that times the amp rating for your panels, times the number of panels, and you have an idea of how much electricity you can get from the sun. There are other factors: time of year and tilt of your array, battery charger efficiency, etc. But the concepts that apply to a home/stationary solar setup are exactly the same as those used to size a mobile setup. You just have to take into account that the whole setup can & will move at 65+mph, bounce & vibrate, and may be parked at any given orientation.
To learn about sizing, I recommend the Solar Energy International book titled Design & Installation of Photovoltaics. It was the textbook for a solar class I took a few years ago, so it should be available used & not too expensive.
Some modern solar panels have a 25 year warranty for (I think) 95% of their output. They are made to live outside in the weather. There are also other components (cable/wire, boxes, etc) that are designed & rated for outdoor use. Just use good-quality system components, installed in a sane manner (i.e., grommets where anything passes through a wall, proper wire size, fuses, etc.), along with periodic inspection and regular maintenance (battery water levels, checking connections, etc) and your system should last a long time.