This grinder I adapted from a standard Jupiter electric grinder, and along with a 45Watt solar panel, an old 24V slot machine motor, and a hand made adpater, the unit will put out enough flour in a sunny afternoon to make at least 3 good loaves. Since the motor is rated at 24V, it will run all day on the 12V from the panel, and does not overheat. Trying this on 24V will shorten the life of the motor when run for several hours at a time. Also, running at 12V is slow, so the grains do not heat up when grinding unlike some other more modern methods. I will be glad to do a post on how to build this if there is interest.