For millennia, the wind has been harnessed for work.
The Dutch wind mill is probably the most recognized structure from days of old but in fact, the wind has been utilized as far back as 200 BC.
Modern technology has allowed for a far more efficient harvest of wind energy via the generation of electricity.
Alberta has 807 installed mega watts of wind power and Canada has 4,588 MW with another 1,000 megawatts forecasted to be installed in 2011.
In off-grid installations, be it the remote fishing lodge or residence, small wind turbines play an important role in the alternate energy arrangement.
Wind generators are driven by a variety of turbine configuration and have two basic types.
• The horizontal axis wind turbine (HAWT) is probably the most common with its propeller like blades facing the wind, and are commonly seen lining the ridges of Pincher Creek, Trochu, and dotting the oceans around Norway and Denmark.
• The vertical axis wind turbine is (VAWT) is the second type and is divided into three sub categories.
The Darrieus is named after its inventor Frenchman Georges Darrieus.
It has an “eggbeater” type curved blade mounted to a vertical shaft driving the generator. A fairly efficient machine, it unfortunately produces large stress on its tower and needs to be started before the wind can impel it.
The next two subcategories are the Giro-mill and Savonius.
• The Giro-mill, which has straight blades, is relatively efficient, has self-starting capabilities and low stress on the tower, making it a good candidate for areas of higher wind turbulence such as around buildings in urban areas.
• The Savonius is the cup-type turbine which is commonly used by anemometers in weather stations.
A new concept wind turbine has been developed by Honeywell.
It has a turbine which looks remarkably like the intake fan of a jet engine.
In this design, the tips of the blades pass a system of magnets and stators in the outer ring. This design allows for the quiet and highly efficient generation of power in the smallest of breezes.
This model will start to generate power in winds as low as 0.2 m/s, which is notable when compared to one of the most efficient HAWTs, which has a start up speed of 2.0 m/s and a good VAWT with 2.5 m/s.
The Honeywell Blade Tip Power System was designed for the urban setting, allowing it to harvest wind in the turbulent conditions developed around multiple structures.
The type of turbine to use is determined by a number of factors, the first being the location of the installation; trees, buildings, and topography, as well the electrical requirement.
As time goes by, advances in technology, and an increasing number of manufacturers developing more units, will lower the purchase price.
The future bodes well for wind turbines to become commonplace.
Wind the unseen force, will keep making life easier for ordinary folk in either an off-grid or grid tied situation.
Lorne Oja is an energy consultant, power engineer and a partner in a company that installs solar panels, wind turbines and energy control products in Central Alberta. He built his first off-grid home in 2003 and is in the planning stage for his second. His column appears every second Friday in the Advocate. Contact him at: email@example.com