This is really interesting. I spent last night calculating a small solar setup for my property. I have 4x220w panels, 4x100amp deep cycles, and a few inverters: one 1000w, and another 600w. And a 20 amp solar charge controller. Basically the most minimal setup.<p>I was trying to figure out how to design a system that, given 4 hours of full sunlight at the maximum output of the solar charger (300w) or 4 * 300 w = 1200w total daily charging of my deep cycles. If the system is 100% efficient (it isn't), this gives me 50w a hour over a 24 hour period. 1200w / 24 hr = 50w. But my solar panels exceed the ability of the charge controller. How can I use that to my advantage? I have a well and a holding tank. I was trying to figure out a circuit, perhaps an Arduino program/circuit, with voltage/amp sensors and relays to do this: If there is enough sun, charge the battery. If the batteries are full, turn on the well pump into the holding tank (there's a pressure switch to turn it off when the tank is full). And put the holding tank up on the hill -- which should give me 25-30psi (up 45-50ft). Then I was trying to figure out how to optimize my well pump, or use a DC motor. I might look into salvaging a 2hp DC motor from a treadmill and retrofit it onto a pump housing. Anyway I am trying to optimize for extreme budget. 50w an hour isn't a lot, but it is enough to run a few light bulbs and my tiny refrigerator. I might be able to run a RPi and charge some 18650 batteries for flashlights.