Solar Trailer

One of my friends is building a solar trailer. Very cool. I took the Alpha version of the product for a test drive. It's promising but still needs extensive refinement. His purpose is to ride across the United States while making a documentary on sustainable living. Right now the batteries last about 2 hours and the motor tops off at about 15 MPH. It would be cool if he could ride up to 10 hours per day on a single charge. This would allow him to cover 150 miles per day before having to recharge. I realize the extra weight will reduce the top speed and add to strain of the batteries.