As many people within the sustainable energy industry will tell you, getting the power is not hard... containing it for future use is. Researchers at Penn State have developed a new method for recharging batteries with a water-based solution containing CO2 emitted from fossil fuel power plants. This unconventional use of pH level imbalances is what generates electricity. Although this method is new in the lab the process is stable at room temperature and utilizes very inexpensive materials.
These new methods of energy storage are just the beginning for the battery industry. If the system was small enough your RV could charge the house battery bank when driving and then use the solar panel system to top it off and maintain at your stopping point. Companies like AriXsun Energy are going to come out with even smaller solar panels for hikers, bikers and camper van explorers looking for power in a compact size.