Canada's Condominium Magazine
For the first time, wind power now has greater generating capacity in the United States than hydroelectric power, making it the most important source of renewable energy in the country, according to a report in Proud Green Building. The Department of Energy reports that at the end of 2016 installed wind capacity reached 82,183 megawatts, enough to power about 24 million homes. Wind supplied about 5.5 per cent of the country’s electricity in 2016, and in five states it was more than 20 per cent. Iowa got 36.6 per cent of its electricity from wind in 2016. Growth in wind has been aided by federal tax incentives and state mandates that require utilities to buy renewable energy as part of their greenhouse gas-reducing strategies.
Hydroelectric capacity in the US, in comparison, was 78,956 megawatts, but no new hydroelectric projects are planned at this time. Hydroelectric power plants are reportedly more efficient, however, with a rating of 35.8 per cent compared to 32.2 per cent for wind, according to the New York Times citing the Energy Information Administration. This means that hydro still sends more energy to the grid, but improvements in turbine technology are allowing wind to catch up. Wind farms built in 2014 and later have now reached 41.2 per cent efficiency, according to the Department of Energy.
How is Canada doing in the wind energy department? This country finished 2016 with 11,898 megawatts of installed wind capacity, enough to power 3 million homes, according to the Canadian Wind Energy Association (CanWEA). Over the year, twenty-one new projects were completed, sixteen of them with significant ownership among Aboriginal Peoples, and representing an investment of $1.5 billion. Canada now has the eighth largest wind-generating “fleet” in the world. There are now 272 wind farms operating from coast to coast.
Ontario is Canada’s biggest producer and user of wind power, with 4,781 megawatts installed. It supplies about 5 per cent of the province’s electricity demand. According to CanWEA, Ontario’s investment in wind power has so far helped reduce greenhouse gas emissions from the electricity sector by 90 per cent. Ontario was the first jurisdiction in North America to eliminate coal-powered generating plants.
Wind energy is growing in more than 90 countries around the world at an average annual rate of 22 per cent a year because governments, citizens and electricity system operators alike have found a reliable, clean, and safe form of energy, and at a good price.
BC, on the other hand, is not looking for more wind power. The province recently opened its largest ever wind farm, enough to increase its capacity by more than one-third, but BC Hydro has said it will not need additional capacity until 2030.
Wind energy is one of the fastest growing sources of new electricity around the world, according to CanWEA. It is growing in ninety countries at an average annual rate of 22 per cent.
How wind turbines work
Looking at a turbine spinning, one might assume that the wind is “pushing” the blades, but this is not the case, says CanWEA. Rather, the wind, passing over the blades, causes lift, as it does passing over an airplane’s wings. The lift causes the blades to turn, and the kinetic energy of the wind is converted into mechanical energy, which is transmitted through a drive shaft to an electrical generator in the nacelle, the housing for the generating components located behind the blades. That electricity then travels via underground cables to a substation, is converted to higher voltage, and delivered to the electric utility for distribution.
The optimal wind speed for turbines to operate is 14.4–90 kilometres per hour (4–25 metres per second). When the wind exceeds that top speed, the turbine will shut down to avoid damage. At the bottom end of the speed range, and operating at sea level, the turbine produces 196 kilowatts of electricity, enough to power just over 100 homes (assuming a blade diameter of 120 metres). At top speed, the capacity reaches 3338 kilowatts, enough for 1823 homes. These conditions are met about 85 per cent of the time.
Wind forecasting techniques today allow utilities and grid operators to anticipate and plan for variations in wind energy output. CanWEA says that wind is a natural partner with hydro, as the wind blows strongest in winter when water reservoirs are at their lowest.
Hydroelectricity still dominant
Hydroelectricity continues to provide the largest component of Canada’s energy mix. The country currently has 542 hydroelectric stations with 78,359 megawatts of installed capacity. In 2014, according to Natural Resources Canada, hydroelectricity accounted for almost 60 per cent of the country’s electricity generation, making Canada the world’s second largest producer. Quebec is by far the largest producer and exporter of hydroelectricity in the country with over 40,000 megawatts of capacity; BC is a distant second with about 15,000 megawatts, followed by Ontario with about 10,000.