Well the most simple way of turning wind energy to hot water is to just turn a water pump shaft and circulate water through a closed system such as an insulated tank. All of the shaft power of the pump that moves the water is turned to heat. You can actually buy hot tubs that have no heater. They just cycle the pump on and off to heat and maintain water temperature. My hot tub now has a heat pump. However, if I forget to turn the high speed water pump off, the hot tub can hit 55 degrees C or 131 degrees F.
