Fact Sheet: Wind Power Realities
Harnessing the power of the wind has become one of the fastest growing sources of global electricity generation.
As countries strive to develop clean and secure energy systems, more scientists, policy makers and communities are looking to wind power as an important part of the solution.
As new opportunities emerge to develop wind-power generation in communities across Canada, they raise reasonable questions about the social, environmental and economic impacts of large-scale wind power production.
This fact sheet aims to help answer those questions, and to distill the realities of wind power from the myths and misconceptions.
Wind Power: Overview
The energy from the wind can be harnessed by wind turbines to generate electricity and also windmills to pump water.
During the 1990s, wind turbines evolved dramatically to become very large and increasingly efficient machines, as a direct result of government policies set in Denmark enabling communities and co-ops to develop wind turbines and encouraging research and development.
Chart: Global Annual Wind Installations (MW) 1980-2005
Capturing and Using Wind
Modern wind turbines generate electricity typically around 80% of the time. The output varies depending on wind speed, but over the course of a year, a turbine is designed and expected to generate about 30% of its theoretical maximum output. This is known as its capacity factor, which for conventional power plants is typically 50%.
Although the wind does not always blow, one region may be calm while another one is windy. Therefore, overall fluctuations can be significantly reduced if wind turbines are spread out across a country or region.
Wind turbines tend to generate more power during the day when it is needed most and less at night, a pattern that corresponds well to electricity demand. Wind power therefore combines well with existing power plants in Canada that can be used only when needed, such as hydro plants, or must-run power plants like biomass that tend to have excess power at night.
The energy that is available in the wind is cubically related to the speed at which it is moving. In other words, doubling the wind speed means there is eight times more energy. A good wind power site therefore needs to be consistently windy. Even small differences in wind speed can have a large impact on the performance a project.
Wind energy can also be used for mechanical work such as water pumping and small-scale power systems for homes and small businesses. Canada has a unique expertise and manufacturing ability for medium-scale electrical systems that are ideally suited for remote community applications and hybrid systems such as wind-diesel.
- Large-scale wind energy is becoming cost competitive with traditional power generation.
- Very low cradle-to-grave impacts.
- Wind is abundant all over the world.
- Wind patterns tend to follow consumption patterns.
- Turbines co-exist nicely with farms, supplying additional income with minimal impact on the usable land.
- Wind turbines are very quiet and are less likely to be struck by a bird than a downtown building, a bay window or a car is.
- Significant local visual impact.
- Moving parts require maintenance and upkeep.
- A consistent and considerable amount of wind is needed.
- Bats can be affected or struck by turbines.
- Power output is variable and needs overall system integration.
Global Status and Potential
Global wind energy capacity has sustained growth rates over 25% for the past 15 years primarily because wind energy has become a cost-effective source of renewable energy. Western Europe has been the early technology adopter and, as a result, has also become the early leaders in technology development. Denmark, Germany and Spain are the world leaders in wind energy manufacturing.
Wind energy's growth has been so rapid that there is currently a one- to two-year waiting period to receive a turbine after it has been ordered. There are now over 68,000 operational wind turbines.
Canadian Status and Potential
Canada ranks behind the United States and most European countries in wind energy installation. Despite a slower start, Canada is currently experiencing an annual 30% growth rate in wind energy development, a rate comparable to global development.
Wind turbine technology is improving rapidly. For example, in the year 2000 a state-of-the-art turbine was 1.0 MW; now 4.5 MW machines are on the market. In this context it is difficult to quantify what a country's maximum potential is, but a 20% supply, similar to that already deployed in Denmark is reasonably achievable.
The Canadian Wind Energy Association's goal is for 10,000 MW of installed wind energy in Canada by the year 2010, enough to supply 5% of Canada's electricity needs. Denmark currently generates over 20% of its power from the wind, an attainable goal for Canada. If wind energy were to generate 20% of Canada's electricity, it would be the second largest source of electricity behind hydro and ahead of nuclear, natural gas and coal.
Recent growth in Canada owes much to federal and provincial policy measures that have enabled or encouraged wind energy development. It is crucial that the government creates a level playing field for wind energy so that it can compete with conventional energy.
Links for more information
- Canadian Wind Energy Association (CanWEA)
- CanWEA: Canada's Wind Farms (Installed Capacity)
- American Wind Energy Association
- Danish Wind Industry Association
- Environment Canada: Wind Energy Atlas
- Pollution Probe's Primer on the Technologies of Renewable Energy