Based only on my assumptions, but dealing with solar panels fairly regularly for solar-powered security cams, it's probably a size/efficiency thing. Spinning a

Based only on my assumptions, but dealing with solar panels fairly regularly for solar-powered security cams, it's probably a size/efficiency thing. Spinning a motor takes a fair amount of power, and they probably want the entire unit to be as small as possible. So I'm guessing he is starting with higher-efficiency panels (more power output per given area), and then possibly modifying them to run on different voltages for the motors.