Wind Energy Facts
- Why does the Wind blow?
Like all forms of energy, wind is created as a result of the sun. The sun heats a land mass and the heat from the land is absorbed by the surrounding air. When the air reaches a certain temperature, it begins to rise quickly upwards. This results in a low pressure area at ground level and a higher pressure area above the land. Air naturally moves from high pressure zones to low pressure zones. This air movement creates wind.
- Wind Turbines Whisper Quietly
Wind turbines operate under windy conditions, the harder the wind blows the faster the turbine turns. However, much of the sound from the blades is masked by the sound of the wind itself and of the accompanying sound of rustling leaves in nearby trees and shrubs. At distances over 200 meters, during normal wind speeds, the ‘swishing’ sound of rotor blades is usually masked completely by wind noise in the leaves of trees or shrubs. Any mechanical device has the potential for mechanical noise – the sound that is emitted when two parts rub together. The good news is that this type of sound has virtually disappeared from today’s well engineered modern turbine. With today’s turbine technology it is possible to stand at the base of a wind turbine and converse in normal tones. The Enercon E-82 turbines installed at the Bear Mountain Wind Park are gearless turbines which emit virtually no mechanical sounds. The wind park has the quietest wind power technology currently available in the world.
- Wind Energy is Clean, and Saves Energy
Can a wind turbine ever recover the energy spent in producing, maintaining and servicing it? Wind turbines use only the energy from the moving air to generate electricity. Wind energy leaves no harmful emissions or residue in the environment. Compared to a coal burning generator, a wind turbine can displace 1,900 tonnes of C02 (carbon dioxide) and five to eight tonnes of NOx (nitrogen oxides) and SO2 (sulphur dioxide) per year. The energy produced by a wind turbine throughout its 20 – 25 year lifetime (in an average location) is 80 times larger than the amount of energy used to build, maintain, operate, dismantle and scrap it again. In other words, it takes only about three months for a wind turbine to recover all the energy required to build and operate it.
- Wind Energy is Abundant
Wind resources are plentiful. In 2014, global wind energy capacity grew by 44 per cent, with the wind industry installing a record level of 51.5 GW of new clean, reliable wind power. By 2015 the worldwide cumulative installed capacity from wind power amounted to 432,883 MW. Today, there are over 314,000 wind turbines operating around the world in over 90 countries according to the Global Wind Energy Council. In Canada, wind energy production has grown to 11,205 MW; enough to power more than 3,300,000 homes. Wind will not run out. Since 1993 Canadian wind turbine installations and wind parks have spread across the provinces from the Yukon, the Peace Region of British Columbia, Pincher Creek and Taber in Southern Alberta, through Saskatchewan, Manitoba and Ontario to the Gaspé region of Quebec, and into the east coast provinces.
- Wind Energy Makes a Difference
Wind Turbines have grown dramatically in size and power output. A modern wind turbine such as Enercon’s E-82 typically has a rotor diameter of 82 metres (269 feet) and a 2000 kW generator. It will produce between 4,000 and 6,000 megawatt hours in a year. This is equivalent to the annual electricity consumption of 400 to 600 Canadian households. Worldwide, over 432,883 MW capacity has been installed to date. In an average wind energy year, the EU’s current wind power capacity covers 11.4% of the EU’s electricity consumption. 49% of all the electricity used by South Australians in June 2016 was generated by wind power, and on occasions during the month provided all the state’s electricity needs. The W.A.C. Bennett Dam (G.M. Shrum Generator), in comparison, has a capacity of 2,730 MW and floods 166,000 hectares (410,000 acres). In other words, worldwide power generated by wind turbines already replaces the need for 158 dams the size of W.A.C. Bennet Dam and the flooding of more than 26 million hectares of land. In 2015, wind power avoided over 637 million tonnes of CO2 emissions globally.
- Wind Energy is an Advancing Technology
Technological advances in aerodynamics, structural dynamics and micro- meteorology have contributed to a five per cent annual increase in the energy yield per square metre of rotor area (1998-2001). New technology is continuously being introduced in new wind turbines. The weight of Danish wind turbines has halved in five years, the sound level has halved in three years, and the annual energy output per turbine has increased 100-fold in 15 years. Currently, the world’s largest-capacity wind turbine since its introduction in 2014 is the Vestas V164 which has a rated capacity of 8.0 MW, has an overall height of 220 m (722 ft), a diameter of 164 m (538 ft), and is for offshore use.
- Wind Energy is Inexpensive
Wind energy has become the least expensive renewable energy technology in existence. Since the energy contents of the wind varies with the cube of the wind speed, the economics of wind energy depends heavily on how windy the site is. There are generally economies of scale when building wind parks of many turbines. Wind energy production costs were approximately $0.04/kWh in 2011-12 according to the U.S. Department of Energy. This has been declining as technology improves.
- Wind Turbines are Efficient
The maximum power that can be captured from the wind is 59% of the kinetic energy in the wind (Betz law). Today’s turbines capture more than 50% of the available kinetic energy. The speed of the wind, the temperature of the air, the sweep area of the blades and the height of the tower all influence the power generated.
- Wind Energy is Safe
Wind energy has a proven safety record. Modern wind turbines have a design life of at least 20 years in all weather extremes expected to occur in their operational environment. All major manufacturers use international safety standards in turbine design. Compliance to these standards is audited by third party organizations.Wind turbines have special inbuilt safety equipment to deal with emergencies. They are equipped with vibration sensors to detect rotor problems. All modern turbines allow complete shut down during excessive wind speeds, virtually eliminating the risk of the turbine rotor or tower failing. The blades on some models are designed so that ice is detected as an uneven load and the turbine will shut down immediately. Many manufacturers also have monitoring systems to keep the turbines under 24/7 surveillance. Wind turbines also produce no harmful emissions in the generation of electricity. Wind turbines are considered so safe that at many windparks on public lands around the world, people may walk to the base of the turbines at any time, animals graze under them and farmers plant and harvest to the base of them.
- Wind Turbines are Reliable
High quality modern wind turbines are operational on average, or ready to run, during more than 98 per cent of the time. This is better than any other electricity generating technology.
- Wind Energy Uses Land Resources Sparingly
Wind turbines and access roads occupy less than one per cent of the area in a typical wind park. The remaining 99 per cent of the land can be used for farming or grazing, as usual. Wind power farms generate between 17 and 39 times as much power as they consume, compared to 16 times for nuclear plants and 11 times for coal plants.
- Wind Turbines Coexist Peacefully with Wildlife
Deer and cattle habitually graze under wind turbines, and sheep seek shelter around them. Wind energy development’s impact on birds and bats is extremely low compared to other human-related activities, such as vehicles, buildings, housecats, high tension lines or habitat loss. Wind turbines with smooth sided towers reduce nesting sites, and many turbines have slower rotation speeds, thereby reducing risk to birds and bats.
- Wind Energy Integrates Well into the Electrical Grid
Wind power is variable, but wind tends to match consumers’ daytime peak demand for power. Also, it fits well into hydro-based grids whereby dams store water. When the wind is not blowing, stored water is used to produce power instead.
- Wind Energy Provides Jobs
By the end of 2015 the wind energy industry provided more than 1,100,000 jobs worldwide. Last year the wind energy industry grew by 44%. The total value of wind energy investment globally by 2016 was US$ 109 billion. In 2015, clean wind energy grew by 23 per cent in Canada, representing over $3 billion in investment and creating 10,500 jobs. For every megawatt of wind energy, the number of jobs generated ranges from approximately 10 to 14 full-time equivalent (FTE) jobs for one year. Wind energy developments create a range of job opportunities at both the construction stage and when the wind farm is operational. Achieving the minimum goal of 10,000 MW of installed wind energy capacity in the country has meant, among other benefits, thousands of jobs in manufacturing, project development, operations and maintenance. The wind industry is becoming more multinational, as the industry matures and more manufacturing is established in new markets. For example, in Denmark alone, more than 20,000 people make a living from wind energy, designing and manufacturing wind turbines, components, or rendering consultancy and engineering services and operating and maintaining turbines.
- Wind Energy is Popular
As of the end of 2015, worldwide, total cumulative installed capacity from wind power amounted to 432,883 MW and increased by 17% compared to the previous year (369,553 MW). In 2015, China installed close to half of the world’s added wind power capacity. Global wind power installations increased by 63,330 MW, 51,447 MW and 35,467 MW in 2015, 2014 and 2013 respectively. 26 countries have more than 1,000 MW of wind power installed across the world; 14 countries have installed more than 5,000 MW and 8 with more than 10 GW installed. Wind turbines tend to be good tourist attractions when they are new in an area, and large wind developers often establish visitors’ centres at their wind parks. It is also generally popular with people who hold environmental values. Wind energy will help us to meet Kyoto targets by reducing greenhouse gases. In 2015, wind power avoided over 637 million tonnes of CO2 emissions globally.