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Wind energy has been used for centuries, for grinding grain, pumping water and generating electricity. Small wind turbines were an important source of electricity for rural families in North America in the 1920s and 1930s. Wind energy faded into the background with the rural electrification efforts of the 1940s and the development of reliable small engine generators.

Today, we are seeing wind gaining tremendous popularity in generating significant amounts of power both off-grid and as a source of energy for large utilities. European countries are leading the way in wind generation while Canada generally lags behind. Alberta has an established base of large-scale wind generators. Downtown Toronto now has a commercial-scale turbine

How it works
Wind turns the blades of the turbine which spins a shaft within the turbine structure. The shaft drives a generator to produce electricity. The electricity is either used directly or stored in batteries.

Types of Wind Generators
There are many different types and styles of wind generators. Many of the older, multi-blade units as seen on farms across the nation generate mechanical energy, often used to pump water.

  • Small-scale units (under 3 kW): used to charge batteries or direct use (such as pumping water or grid intertie). Purchase Online
  • Medium sized units (up to 50 kW): used in a grid-intertie environment to generate power and feed it to the utility grid. Energy Alternatives designs and installs medium scale units. Due to the nature of these projects, each system requires a detailed assessment prior to quotation or ordering products. Investment is typically $40,000+.
  • Large-scale units (megawatts): large, towering units that cost millions of dollars and generate power to run hundreds or thousands of homes or businesses. Generally suited to large utilities and power co-operatives.

Wind and PV
In many Canadian locations, a wind turbine is an excellent supplement to a solar electric system. Small wind systems are often combined with photovoltaics because seasonal variations in wind and solar resources are complementary. Most places in Canada do not have adequate wind to use as a primary power source. Locations such as the prairies that have constant prevailing winds are most suited to wind power. Contrary to popular belief, coastal areas do not always provide the best source of wind power - the winds are not as constant and predictable as those on the prairies.

Battery Size
Wind is a variable resource. The winds may be calm for a week or more, but when it does become windy it often blows very hard, most notably in the winter. For this reason wind energy systems usually require a larger battery to take advantage of the energy when it is available and to store it for extended calm periods.

Unlike photovoltaic modules, wind turbines have moving parts. Periodic maintenance of bearings, brushes and shafts is required. It is important when installing a wind generator to consider how easy it will be to access the generator and conduct maintenance.

Towers are a critical component of wind power systems. Proper location and height of your tower is necessary to get maximum energy from a wind turbine. Improper tower design or installation may result in personal injury, property damage or a damaged generator. It will also likely result in less-than-satisfactory performance from your wind turbine.

You should be completely familiar with the installation procedures before you begin. Safety equipment should be used at all times. Check your local building department for bylaw or zoning restrictions for towers.

Tower Height
Wind generator operation is dependent on the quantity and quality of the wind hitting the blades. Turbulent wind will reduce the power output as the turbine swings back and forth hunting for the wind. The unequal stresses caused by turbulence and the variation in wind speed between the upper and lower blades of a wind turbine installed too close to the ground will reduce power output and wind turbine life.

Wind speed increases rapidly with tower height. Doubling tower height increases the available wind power by about 40%. It is often more economical to install a higher tower rather than purchasing a larger generator. A wind generator should be installed a minimum of 33 feet (10 meters) above any obstruction within 330 feet (100 meters).

Tower Construction
Guyed towers are economical and are able to withstand very high winds if properly installed. They require a fairly large area of cleared land around the tower to facilitate the installation of the guy lines. To supply the desired amount of support and keep the stresses on the tower to a minimum, the guy lines should extend as far as possible around the tower to a maximum radius of 80% of the tower height. Guyed towers may be either lattice towers or tubular towers. The tubular towers are frequently designed for tilt up installation. They have the advantage of easy installation and turbine maintenance.

Self-supporting towers are the least visibly intrusive wind turbine towers. They can be installed in rough terrain with a minimum of cleared area. Very small wind turbines may be installed on a short self-supporting tubular tower, but larger turbines require a lattice tower.

Tower grounding rods and wire provide lightning protection and assure a low resistance path to ground. The grounding wire should be straight, without sharp angles.

What you need for a wind system

• Wind generation is dependent on the quality and quantity of the wind hitting the blades. The better the wind you have, the more power you will generate.
• The power available in wind increases by the cube of the wind speed - if wind speed doubles, power output increases by eight.
• Turbulent wind (from obstructions, geographical features, etc.) will reduce the power output as the turbine swings back and forth hunting for the wind.

A Good Site
• The higher a turbine, the more power is generated, the better quality the wind.
• A wind turbine should be at least 40 ft above any object within a 400 ft radius. Note there are often exceptions to this rule depending on your site.
• It is often more economical to install a higher tower than purchasing a larger turbine.
• Space. Generally locations with an acre or more will be suitable. Most urban locations will not permit you to install a wind generator in your yard. A guyed tower requires 1/2 the height of the tower as a radius at a minimum for location of anchor points. Space is also required for ground assembly and erection of the tower. Lattice towers require less surface area, but are more complex and expensive to install.

Get the data

Measuring Wind
There are three primary ways of determining how much wind is available on your site:

1. Installing an anemometer:
• The most accurate way to determine wind speed.
• Can take several years of readings and some expensive equipment to compile accurate data - unless you plan on spending $15 000 or more on a wind energy system, this is usually not a necessary step.
• Inexpensive anemometers can be read manually on a daily or weekly basis - a minimum of 3 months of data should be recorded and correlated with another source of wind data for a small wind generator.
• Some people install a small wind generator and use it as an anemometer if they are planning for a much larger installation.
• Home weather stations will often have a facility to measure wind speed - this may or may not be completely accurate, but will allow you to notice trends in speed and direction.

2. Using existing data:
• Local airport or meteorological stations.
• Universities, colleges and radio stations.
• There may be some data from government sources, but unless a weather station is nearby the data may not be accurate for your site.
• Wind speeds can vary a great deal within a small area, so this information should be correlated with another method such as visual observations.

3. Visual observations (the Griggs-Putnam Index):
• The simplest and quickest method of determining average wind speed is to observe the effects on vegetation at the site.
• If the trees or shrubs are growing with a definite slant to one direction, or only branches on one side of the tree, you will have a very good wind site. It takes constant, prevailing winds to affect vegetation in this way.
• If you have a flag at your site and the flag is stiff in the wind for a few hours a day then the site is a good candidate for wind power. Keep a log book of flagpole observations to help give you some idea.
• Flying a kite is a lot of fun and lets you get to know the wind at your site and offers you some predictions as to what height of tower will be best for your site.
• If there is another wind turbine in your area, track down the owner or person responsible and they will more than likely be willing to share their observations of wind patterns

Purchase Products Online:

Wind Turbines
Wind Towers
Wind Accessories

Blowing in the Wind. With the right wind site, wind power can be an exciting renewable energy alternative for cottagers.

An Introduction to Wind Systems
One of nature's renewable energy resources, the wind can be harnessed to provide an environmentally friendly and reliable source of energy.

A Buyers Guide to Wind Systems
Published by Natural Resources Canada, this is an excellent guide to educate you on this exciting technology.

Wind-Electric Systems Simplified - HomePower article . An introduction to the basic components of wind-electric systems, and a rundown of the most common system configurations.

Tax Incentives for Renewable Energy Systems

Rescreen - software to calculate energy production, costs, etc of small to large scale wind projects

Homepower magazine has an excellent, 24 page article "Choosing a Home-Sized Wind Generator". This is an excellent article by Mick Sagrillo, who has been installing and tinkering with wind generators for the last 22 years. - An image library of European installations

The US National Wind Technology Center

The European Wind Energy Association

The Canadian Wind Energy Association

The British Wind Energy Association

US National Renewable Energy


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