The turbine provides a  48volt 3 phase output which is rectified and charges a 600 Amp/hr 48 volt lead acid battery.


Some power is used directly to heat water in the kitchen and for the shower.


240 volts a.c. mains is produced from the battery via a 4.5 kW pure sine wave inverter.

Inverter power is fed to some household and bookshop circuits which means that the bookshop computers, lighting and telephone exchange need never be affected by power cuts.

If there is insufficient wind, power is taken from the grid.

Our power provider is Good Energy.

When the battery is fully charged excess wind power is used to heat water and other heating loads directly.


The site is exposed to winds from the East round to the North West. Prevailing south-westerlies whistle across the fields unhindered.

The house and bookshop shelter the turbine a little from winds from other directions. This causes turbulence - bad news for turbines.

Winds, and therefore power, are more plentiful during the winter months.

The power in the wind is proportional to the cube of the windspeed. i.e a little more wind means a lot more power.


The turbine starts to produce power in about a 6 mph wind. At 15 mph 2 kW is generated rising to 6 kW at 23 mph.

Although the power is not metered an estimated 9,000 kW/hours is generated annually - approximately a third of the needs of the house and bookshop.


Even with no wind the battery has enough capacity to keep the business running all day (including kettle!) when power cuts strike. In a fresh breeze we need never close!


Cost (in 1999)

Full installation £15,000 (+VAT).

No grant aid was sought.

As the output is not metered no ROCs are claimed.


It will be approximately 16 years before the installation pays for itself, depending on maintenance costs and future electricity price rises. The turbine has a life expectancy in excess of 25 years - 25 years of felling good!



If you go to the Proven website you will see that they make smaller and larger turbines than ours.

When calculating the size that you need remember that the power output quoted is the maximum power in a high wind. For small turbines multiply by approx. 0.22 to get the average power for a windy location with little turbulence.

Always get the highest possible pole!


Links

Proven Engineering

Good Energy

British Wind Energy Association


Unity Wind Ltd. - A community wind project for North Walsham and perhaps more!