Wind power to immersion?

Ubbquittious

Instead of messing around with grid tie inverters for wind turbines which seem to be getting scarce now if you don't want cheap Chinese crap is there any gain to be had from connecting one directly to an immersion heater?

I was thinking of getting a 500w-1kw turbine and connecting it to a MPPT tracker + charge pump and have it only supply the immersion. I'd use solar panels but I have no south facing roof on this house at all


Just in case you're wondering how I came up with such a daft idea it was when I went to Shetland a few years ago a crowd called SHEAP were wanting to do this on an industrial scale and pump the resulting hot water to all the houses but I don't know if it ever went anywhere

quentingargan

Its the MPPT tracking that is the tricky bit of what you propose. The relationship between energy available from a turbine and its voltage is an exponential one, so you can't just put it onto resistor. You need a complex PWM device to manage this. And what happens when the immersion is hot enough? The turbine then needs another load anyhow.

Also, you can heat water relatively cheaply with oil or gas at between 5c and 9c per KwHr, whereas electricity is worth 16c or so (if you can use it). So it makes more sense to convert the electricity to grid using an inverter. There are proprietary devices that can then send your surplus power to the immersion. You can get small wind inverters for about €850 plus VAT. I doubt you'll make another working MPPT device for much less.

But for domestic scale, wind is expensive and troublesome compared to solar. A north facing roof at 30 degree pitch is 62% of the output of a south facing one, so you would need 50% more panels, but that is cheaper and more trouble-free than wind.