Solar electric systems can be designed for any application you find necessary. They are ideal for remote locations and for powering 12 volt equipment, like travel trailers. Best is a combo solar/wind system or solar/generator system. You can get a small system to power a few lights, or a refrigerator and freezer in case of power outages, and grow they system as funds are available to power more equipment, say a well pump or whatever.
Their portability is limited by their physical size and need for batteries to maintain power in dark or cloudy times of day. Modular systems can easily be set up to power whatever you need, when needed. Just depends on how much you want to mess with it.
You can get lots of info from Backwoods Home Magazine, backwoodshome.com, which has articles by Jeff Yago about small alternative power systems. He goes into much detail about system sizing and gives formulas to figure how much you need to produce to power what you want to run. He even has an article about a cargo trailer he converted into a portable generating station.
Study it out, then go for it.