Wind Power
What is It?
Modern wind turbine technology is a result of advancements in aerodynamics, electrical engineering, electronics, instrumentation and meteorology, all of which have immensely improved the performance and efficiency of the modern wind turbine.
Wind turbines, like windmills, are mounted on a tower to capture the most energy. At 100 feet (30 meters) or more aboveground, they can take advantage of the faster and less turbulent wind. Turbines catch the wind's energy with their propeller-like blades. Usually, two or three blades are mounted on a shaft to form a rotor.
A blade acts much like an airplane wing. When the wind blows, a pocket of low-pressure air forms on the downwind side of the blade. The low-pressure air pocket then pulls the blade toward it, causing the rotor to turn. This is called lift. The force of the lift is actually much stronger than the wind's force against the front side of the blade, which is called drag. The combination of lift and drag causes the rotor to spin like a propeller, and the turning shaft spins a generator to make electricity.
Typical wind turbines can now generate up to 3 megawatts (MW) of electricity each and are 200 times more efficient than they were two decades ago.
Efficiency gains from technological advancements have also made wind power more competitive, with the cost of wind generated electricity dropping by 80% in just 20 years.
The generation of energy using wind creates no emissions. Properly designed and sited, wind power is one of the cleanest, greenest energy generation technologies in the world.
Why Wind?
Wind generated power is clean, renewable, proven and cost competitive.
Wind energy projects are operating in over 70 countries around the world as well as in every other province in Canada.
Applications
Wind turbines can be used as stand-alone applications, or they can be connected to a utility power grid or even combined with a photovoltaic (solar cell) system. For utility-scale (megawatt-sized) sources of wind energy, a large number of wind turbines are usually built close together to form a wind plant. Several electricity providers today use wind plants to supply power to their customers.
Stand-alone wind turbines are typically used for water pumping or communications. However, homeowners, farmers, and ranchers in windy areas can also use wind turbines as a way to cut their electric bills.
Small wind systems also have potential as distributed energy resources. Distributed energy resources refer to a variety of small, modular power-generating technologies that can be combined to improve the operation of the electricity delivery system.
The Technology
Modern wind turbines spin the blades and convert wind into electricity. Wind turbines sit atop towers so that the blades of the turbine are free of obstacles and take advantage of higher and more constant wind speeds. When the blades turn in the wind the mechanical power is used to turn a generator and produce electricity. Cables carry this electrical current to transmission lines that then carry it to homes and businesses.
The modern commercial scale onshore wind turbine typically stands 70 to 138 meters tall, with three blades each 35 to 45 meters in length. Offshore turbines can have blades exceeding 50 meters in length.
A 2 MW turbine can generate the equivalent annual power usage of over 500 homes.
The most economical and environmentally responsible way of generating wind energy is to develop wind projects with multiple wind turbines that use only one transmission line right-of-way; providing more power with a smaller environmental footprint.
Environmental Considerations
A typical 100 megawatt (MW) wind energy project will produce 306,600 megawatt hours (MWh) of green energy annually and would displace approximately 215,000 tonnes of carbon dioxide, the equivalent of taking 45,000 cars off the road each year.
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