The vast majority of homes in the British Isles have an immersion hot water tank containing 90 to 200ltrs of water. Most tanks have one or two mains powered (circa 230volt) water heating elements in the tank.
I measured the elements in my tank at 19ohms and 27ohms respectively, or yielding 2.7kW and 2kW of power respectively. This makes sense as the first, longer element is on when the the immersion is set to "Bath" and the shorter element is on when the switch is set to "Sink". (The elements enter the tank from above and hot water is drawn off from the top). I am told the the 19ohm, 2.7kW, element is typical in tanks with one element or those that are fed with an in-line water heating element.
I have a 3 phase, nominally 192v, wind turbine, max power 1.5kW. I would like to have it drive one or other heating element but preferably the 19ohm element.
I am aware of the difficulty of presenting a large load to a wind turbine in that it will act as a very effective brake. I have read most, I think, of what has been said here over the years on the subject of resistive heating. The view seems to be that Maximum Power Point Tracking (MPPT) and/or Pulse Width Modulation (PWM) controllers are required to get the most effective transfer of wind energy into water thermal energy. There is also the problem that the elements have safety heat sensors which switch out the element when a preset temperature is reached meaning that turbine power must then go to a dump load.
Are there any suitable commercial controllers or drawings/schematics of same
available? Any one done this already?
TIA.
