St. Mary Magdalene Church, with Te Apiti wind farm in the background, Ashhurst New Zealand photo credit: Albie Brown
Wind is a renewable energy. It produces no air or water pollution. Wind turbines capture the energy generated by wind and convert it into electricity. The blades of the turbine are rotated by the wind which turns an internal rotor that moves a shaft that then spins a generator and creates electricity.
Wind farms (land-based and off-shore) can generate enough electricity to provide power for millions of people. Wind turbines can also be used by individual farmers or landowners to create mechanical power for their own use, for example, to pump water or aerate ponds or to generate electricity.
Wind energy around the world
- 110 offshore wind farms worldwide
- Denmark generates nearly half (47%) of its electricity from wind power.
- China has world’s largest wind farm
Wind energy in Canada
Canada is generating wind energy across the country in every province and in two of the three northern territories.
Here are some Canadian numbers from the Canadian Wind Energy Association
- 300 wind farms
- 6,596 turbines
- generate enough power to meet the needs of 3.3 million homes
- 8th in the world in installed capacity
Ontario is the province with the most wind farms, with 96 projects for a total of 2577 turbines.
A New Zealand wind energy story
I grew up in one of the best places in the world for wind generation, New Zealand’s Manawatu region.
The tiny village of Ashhurst about 10 km from Palmerston North sits in a valley, below the Ruahine Ranges and at one end of the Manawatu Gorge. The gorge acts like a wind tunnel so it’s pretty much always windy in Ashhurst. As a kid, I remember my mother’s despair as she watched her beautiful gladioli garden being flattened and the laundry wrapping itself around the outside rotary clothesline.
Today wind energy is producing more than six per cent of the electricity consumed by New Zealanders which is about the amount of electricity 300,000 Kiwi homes use in a year. Two of New Zealand’s 19 wind farms sit on the sides of the Manawatu Gorge.
Te Apiti is to the north on the Ruahine hills above Ashhurst, the blades of its turbines looking like huge white birds in the sky. Te Apiti was New Zealand’s first wind farm to supply electricity to the natural grid. The farm’s 55 turbines have a total capacity of 90 MW and generate electricity to meet the annual needs of approximately 45,000 average homes.
The Tararua wind farm is on the Tararua Ranges south of the Manawatu Gorge and is New Zealand’s largest wind farm. Built in three stages, the wind farm has a total of 134 turbines able to meet the electricity needs of approximately 87,000 households.
In New Zealand, opposition to wind farms is generally low. A 2010 University of Otago report concluded there was a high level of public support for wind generation projects although siting decisions were crucial for social acceptability and not all sites are equal in terms of public opinion. From the main street of Ashhurst, behind the local Anglican Church, Te Apiti is one example of a good siting decision.
Wind farms the pros and the cons
No matter where a wind farm is located, it comes with pros and cons, its supporters and its protesters.
Here are the main arguments against wind farms.
Danger to wildlife
Flying birds and bats can be injured or killed if they run into the turbine blades when they are spinning.
Noise and health concerns
Wind turbines generate a low level of noise which some people believe can cause adverse health effects. A Health Canada study in 2014 on wind turbine noise and health found that wind turbine noise exposure was not associated with medical illnesses and health conditions.
A review of 60 research studies conducted worldwide on wind turbines and human health was published in Frontiers in Public Health and the authors concluded that when sited properly, wind turbines are not related to health effects in humans though they may be a source of annoyance for some people.
Technological advancements and newer designs mean the newer turbines are much quieter and there is a reduction in noise complaints.
Visual pollution
The huge wind turbines and large transmission systems required to carry the electricity from rural areas, where most wind farms are located to where the electricity is needed are an eyesore on the landscape.
Here are some of the benefits
No greenhouse gases
Since wind energy doesn’t rely on fossil fuels to power the turbines, wind energy does not contribute to climate change by emitting greenhouse gases during energy production. The only time that wind energy indirectly releases greenhouse gases is during the manufacturing and transport of the wind turbines, as well as during the installation process.
Free fuel
Since wind turbines themselves run strictly on the power of wind generated, there is no need for fuel. Once the turbine is complete and installed, it doesn’t need to be fueled or connected to power to continue working.
We won’t run out of wind
Traditionally we relied on materials such as coal and oil to provide us with the energy we need. These sources of energy are not only causing immense environmental harm but they are not renewable and will eventually run out.
Small footprint
Wind turbines take up little space at the ground level and don’t disrupt farm work. Energy suppliers pay the farm owners to build wind turbines on their land and they can continue to farm without disruption.
Creates jobs
The wind industry creates jobs in manufacturing, construction and local services.
What’s a watt?
Electricity is measured in units of power called watts.
- LED light bulbs for lamps use between six and nine watts.
- One megawatt (MW) = 1,000 kilowatts = 1,000,000 watts
- One gigawatt(GW) = 1,000 megawatts = 1 billion watts.
A turbine with a rated capacity of 2MW will produce enough electricity to power approximately 500 Canadian homes for one year.
By the end of 2018, the overall capacity of all wind turbines installed worldwide reached 597GW.
The bottom line
A sizeable part of the answer to climate change is blowin’ in the wind.
