Monday, 20 February 2012

Wind Energy in the Home

Wind energy is a power that has been harnessed for centuries and calls to mind familiar images of wind mills throughout the world. Today power companies use the wind's energy to generate electricity, but how can you use it? Installing your own personal wind turbine is a green way of generating your own electricity; it is clean, renewable, and produces no greenhouse gases.

Factors to Consider when Buying a Wind Turbine

Wind Speed

Before getting a wind turbine it is important to check the wind speed in your area. To do this, one should refer to wind maps and wind data in their region. Even if the wind data for your location is promising, a hill or other barrier might not be accounted for which would result in wind speeds being greatly reduced. 

There is a great wind speed prediction tool on the website whereby you can enter your postcode and state whether your home is urban or rural. The website can then tell you whether your home is in a suitable location for building a wind turbine.

Wind turbines are very site specific. If wind speeds are below par, then your wind turbine will not produce enough electricity. Wind speeds should be above 18km (10mph) in order for the turbine to generate enough electricity.


The wind speed itself is dependent on a number of factors such as:
- Location (houses built along the coast or on wide open plains are in an ideal location to consider having a wind turbine)
- Nearby obstructions such as buildings and trees
- Height of the turbine above ground level or on top of your roof.


Smaller turbines are susceptible to turbulence, so if you live near to a busy road, or near trees, or in a built up area, a wind turbine is unlikely to work well for you. Turbulent air - where the wind is constantly changing direction - leaves the turbines constantly changing direction, constantly chasing the wind rather than extracting power from it. This is why it is important to build your wind turbine up high because the higher the turbine, the stronger the wind. Also by building your turbine up high, it prevents wind energy from being obstructed. Turbines can be set up either on a pole or on the roof of a house.

Types of Home Turbines

Building Mounted 

Building mounted turbines are smaller systems that can be installed on the roof of a home where there is a suitable wind resource. Often these are around 1kW to 2kW in size. This type of wind turbine is more suited to someone who lives in a residential area. These turbines must be located in exposed areas where wind energy is high. If there are trees or any buildings nearby, then they will cause obstructions which affect the wind speed. The turbine will need to be high enough off the roof so that it will not be affected by turbulence from the roof.

Pole Mounted

Pole mounted turbines are free standing and are erected in a suitably exposed position, often around 5kW to 6kW. Pole mounted turbines are particularly ideal for a person who lives on a large property. It is important that these pole mounted turbines are built high and away from obstructions like buildings or trees. For obvious reasons, this type of wind turbine is not really suitable for someone who lives in an urban residential area.

Building-mounted turbines tend to produce less electricity per kW than pole-mounted ones. A well-sited 6kW turbine can generate approximately 10,000 kWh per year.

In many countries wind turbines require planning permission and there are a number of criteria that a wind turbine will need to meet. If you decide to get a turbine there are many grants and a lot of do-it-yourself (DIY) information on the internet.

If a wind turbine is not right for your home, you can always harness the wind's energy by using it to dry your clothes. Using a dryer can use up a lot of electricity and is not cost effective so why not take advantage of this great energy source!

How Wind Turbines Work

A wind turbine works the opposite of a fan: instead of using electricity to make wind, wind turbines use wind to make electricity. Wind turbines use large blades to catch the wind. When the wind blows, the blades are forced round, driving a turbine which generates electricity. The wind turbine collects kinetic energy from the wind which is then converted into electricity by magnets moving past a stator (stationary part of a rotor system). As the magnets pass the stator, alternating current (AC) electricity is produced. It is then converted into direct current (DC) electricity which can be used to charge the batteries that store the electrical energy or can also be fed into the electricity grid.

Small wind energy systems can be connected to the electricity distribution system. These are called grid-connected systems. A grid-connected wind turbine can reduce your consumption of utility-supplied electricity for lighting, appliances, and electric heat. You can also get stand-alone wind turbines which are not connected to the grid.

Stand-alone turbines: In remote locations, stand-alone systems can be more cost-effective than extending a power line to the electricity grid. But these systems are also used by people who live near the grid and wish to obtain independence from the power provider or demonstrate a commitment to non-polluting energy sources. The stand-alone system uses batteries which store electricity for use during times that your system is not producing electricity due to resource unavailability.

Grid connected turbines: When the turbine cannot deliver the amount of energy you need, the utility makes up the difference. That way the grid can switch between wind energy and the utility company.Grid connected wind turbine will operate only when the utility grid is available. During power outages, the wind turbine is required to shut down due to safety concerns.In some countries like the UK, when the home is linked with the grid any surplus electricity that is produced by the turbine, can be sold to the utility company to reduce and sometimes even eliminate your electric bill. This is known as the feed in tariff.

The stronger the wind, the more electricity produced. Wind is variable and can change day to day so in one day your wind turbine may produce enough electricity to run your house. During periods with not enough wind, the home is supplied power from the utility company or in the case of stand-alone turbines, a battery (with stored electricity) is used. 

Wind resources are strongest in the winter months, while solar resources are stronger in the summer months, so this means that these two energy sources actually work well together and are often used in hybrid systems. A person can switch between the two energy sources. On a cloudy day, a turbine will still produce electricity and on a sunny calm day solar panels will produce electricity.

Sizes of Wind Turbines

Large – these large industrial turbines produce hundreds of megawatts of electricity (expressed as “MW”) and are used by utility companies. Large turbines are usually installed in reserved places called wind farms.

Small – these are ideal for homes, small farms or a small business. They produce no more than 100 kilowatts (KW) of electricity and can be used as a back-up power supply or to decrease energy consumption.

Very small – these turbines are used to charge batteries of a large number of recreational vehicles like small boats.

Homeowners would usually use a small home wind turbine. There are also two types of wind turbines available: horizontal axis and vertical axis. The horizontal axis type comes with a tower, the vertical ones are usually anchored to the ground.

The horizontal axis turbine is the most common and is installed so that it aims directly at the wind. It has a component called a tailvane that will point the turbine to the direction of the wind. The vertical axis type can be installed in whichever way the wind blows, but it needs more ground space to accommodate the wires and other components.

For information about other renewable energies in your home please visit our article on Solar Energy and stay tuned for more!

Thank you for taking the time to learn more about renewable energy - Knowledge Is Power! For more information go to or write to us at if you have questions or want to get involved. Have a green day!