I was looking at building a 12 volt DC system using an alternator from an automobile or something similar with a turbine blade and using a couple 12 volt batteries. I would only be using this charger as needed. The batteries will run LED lights, a radio, maybe some type of aerator and a water pump at my cabin. The acre foot of water is approximately 326,000 gallons and ten months of the year there is at least some water flowing through the discharge pipe. If the 80 GPM figure is right, I should have at least 4075 minutes (67+hours) of charging time in my reservoir. I have a solar charger now but I wanted to try to harness some of the water power that at this point is just running away.