Frequently Asked Questions

The simplest way to think about this is to imagine that a wind turbine works in exactly the opposite way to a fan. Instead of using electricity to make wind, like a fan, turbines use the wind to make electricity.

In a normal residential application, a home is served simultaneously by the wind turbine and the local grid. If there is no wind, there will be no output from the turbine and all of the needed power is purchased from the local electricity supplier. As wind speeds increase, turbine output increases and the amount of power purchased from the utility is proportionately decreased. When the turbine produces more power than the house needs, the extra electricity is sold to back to the grid. All of this is done automatically. This is accomplished by connecting the power output from the turbine to a grid-tied inverter and a smart meter. There is no need for batteries in this configuration.

A residential wind turbine can be a relatively large device and is not suitable for urban or small-lot suburban homes. A property size of one acre or more is desirable to allow for the clearance area around the turbine.

Yes. Wind turbines produce no pollution and by using wind power you will be offsetting pollution that would have been generated by local electricity supplier. Every year, a 11kW C&F wind turbine will offset 14 – 19 tons of CO2 emissions. (0.86kg CO2 per kWh produced).

For most residential systems the cost of taking wind measurements is not justified. Wind resource data published on local authority wind maps is sufficient for an experienced evaluator to predict wind turbine performance. In very hilly or mountainous areas, however, it may be best to collect wind data before purchasing a system to ensure that your site is not in a sheltered area.

Wind turbines do not interfere with TV reception.

Not yet. These turbines are currently intended for the rural residential and small business markets. The rated power outputs are currently 6kW, 11kW & 15kW.

Wind farm turbines are typically in the range of 1,000kW (1MW) and above.

No. A wind turbine is easily retrofitted to virtually any home without the need to change any wiring or appliances. In most cases, the ESB will install a smart meter to measure how much surplus electricity it is purchasing from the turbine owner. This will likely be placed at the main fuse board fore the house.

A 10- or 15- meter tower is supplied along with the wind turbine. Towers this tall are necessary to raise the wind turbine above turbulence generated by obstacles on the ground and trees. Wind velocity and, therefore wind turbine performance, increases with altitude.

The C&F turbines have very few moving parts and do not require any regular maintenance. They are designed for a long life (20 - 30 years) and operate completely automatically.

You should check with your local authority about planning permission, as every local authority may have different regulations.

Wind energy is one of the safest energy technologies. It is a matter of record that no member of the public has ever been injured during the normal operation of a wind turbine, with over 25 years operating experience and with more than 70,000 machines installed around the world.

Maximum Theoretical Power = 0.5 x Swept Area x Air Density x Velocity3

So, the power output of a wind generator is proportional to the area swept by the rotor – i.e. double the swept area and the power output will also double.

Also, the power output of a wind generator is proportional to the cube of the wind speed – i.e. double the wind speed and the power output will increase by a factor of eight (2 x 2 x 2)

At very high wind speeds, i.e. gale force winds, (25 metres/second, 50+ miles/hour) most wind turbines shut down to prevent the fan blades from over speeding. This is accomplished via a mechanical brake system.

The C&F turbine does not require such a brake system, because the turbine can automatically pitch the blades out of the wind, keeping the blades rotating, but not over speeding. When the wind speeds reduces, the blades turn back into the wind, such that the optimum lift-to-drag ratio is achieved.

A visual inspection of the proposed installation site, coupled with the data available from local wind map, may suffice for many sites. A site with an average wind speed of 4-5 meters per second is generally sufficient to make installing a wind turbine worthwhile. To find out the average wind speed in your area you should view local wind maps.

It would be advised to measure the actual speed over a period of at least 4-8 weeks, and the annual average speed can be extrapolated using regional annual data.

A grid-connected turbine will have to disconnect for safety if there is a power cut.