Can I heat water or the building by using electricity produced by the turbine?

Enthusiasts of small scale wind power have found a multitude of ways to utilise the power produced by the turbine. Some use batteries to store electricity for when the wind isn't blowing, others are grid connected, some are pumping water, others are charging electric vehicles, some are powering heat pumps, others are heating water and some are even doing a number of the above from one turbine. Furthermore there is any number of ways to do each of the above.

For a generator that is producing excess electricity, but not able to access the grid or avail of payment from electricity suppliers, storage is often considered.  Charged batteries hold the electricity in the form of chemical energy until it is needed and it is released once again as electrical energy.

Some microgenerators who can not avail of an export tariff opt for a system that will heat water. In this arrangement the electricity is passed through an element in a well insulated water storage tank. The electrical energy is converted to heat energy by the element and the heat is stored in the water tank to be used as needed. The water may need to be heated further by using electricity from the grid before use.

It should be noted that those with access to the export tariff of 9c/kWh or 19c/kWh should probably not consider the added expense of a water heating system from their turbine or microgenerator. Instead they should consider exporting the excess to the grid, receiving the payment, and import the required energy for heating on a reduced night-time tariff.

For those who do not have the option of an export tariff there are three main methods used to heat water from a wind turbine. One way is to just use a mains equivalent supply coming through the existing wiring loop from the grid connected inverter (or direct from an off grid controller) into the immersion element.

Another method is to heat the water via a small bank of wind charged batteries. The batteries provide a buffer from the fluctuations of the wind and provide low voltage direct current (12V, 24V, 48V) for a DC low voltage immersion element which would be a modification added to the well insulated hot water tank. This system could also be incorporated with an inverter and switching mechanism so that the load could be switched to mains voltage AC appliances in the house.

A third method would use a direct heating controller to heat the water tank with a switchover to either heat storage heaters at night or power the home during the day. This method has the advantage that batteries are not needed.

Careful consideration must be given to the method chosen. The demand profile of the premises and the size of the turbine are the key factors. Where no export tariff is available the goal is to design a system which will use every unit of electricity produced without the additional cost of storage.