Grist for the windmill
W ind has the power to lift a kite, fill a sail or soothe the soul. It can also snap trees and destroy entire communities. In the realm of public debate, wind power has become equally volatile.
Ontario has become a flashpoint for the controversy around wind power, particularly since the province introduced its Green Energy Act in 2009. The act mandates diversification of power generation, adding more renewable sources into the mix. It also shifts decision-making from municipalities to the provincial government (although recent amendments have partially undone this change).
Wind has sparked ire in many Ontario communities partly because it is pushed the hardest.
Wind is a mature technology. It is at least twice as efficient as solar, and sometimes better.
“Renewables are going to be part of the mix, and wind just has to be there,” says Rupp Carriveau, Director of the University of Windsor’s Entelligence Research Group, which focuses on renewable energy generation and storage. “Wind is a mature technology. It (is) at least 23 or 24 per cent efficient at energy conversion – twice as efficient as solar, and sometimes better.”
Upsides like this help explain why some rural communities see wind as a key to diversifying local energy and job creation. For instance, wind advocate and Chatham-Kent municipality Mayor Randy Hope has found community buy-in for several major wind projects.
Others, however, see turmoil in wind energy proliferation. In addition to public concern about their physical presence, the variable nature of wind energy presents challenges for the power grid.
Unlike gas, coal and nuclear plants, which provide steady baseload generation, wind turbines only work when the wind blows.
If you have 500 megawatts of wind this minute, it can drop to 50 (the next minute), creating a huge gap in the system.
“On the power grid, supply must be met by demand second-by-second, or you get flickers or rolling blackouts, if a mismatch is severe,” says Jatin Nathwani, a University of Waterloo professor who holds the Ontario Research Chair in Public Policy for Sustainable Energy. “If you have 500 megawatts of wind this minute, it can drop to 50 (the next minute), creating a huge gap in the system and stress over a very short timeframe.”
Nathwani says wind’s variability is manageable with Ontario’s current mix, where it accounts for only about 2,000 of Ontario’s 35,000-megawatt generating capacity. But with plans to increase wind to 10,000 megawatts by 2020, the issue becomes “a challenge to the system.”
That challenge can be met several ways: through improved power storage, regional power-sharing in Quebec, Manitoba and the northeastern United States, or back-up generation systems that kick in when wind power drops. Nathwani says hurdles like these are worth addressing.
“With current policies, Ontario’s greenhouse gases will be about the lowest in the world, with the exception of regions dominated by hydro generation,” he says. “That becomes an Ontario advantage.”
For many communities, wind power remains a difficult sell. Many energy companies now devote major resources to meaningful consultation and education – sometimes household by household – to seek understanding and assent.
While Chatham-Kent’s turbines haven’t escaped controversy, Mayor Hope attributes the general receptivity to massive public engagement, going back years before the Green Energy Act was implemented. “We have always believed in public engagement,” he said. “We were able to put people’s concerns to bed by dealing with facts.”
Carriveau, who has been part of many such community consultations, concurs that power companies can’t win through promotion or education alone. He also sometimes senses that Ontario’s wind energy debate speaks to a more general issue of people wanting more energy, but not wanting any type of generating infrastructure in their backyards. “What alternative would you prefer?” he asks.
Still, he says, no energy infrastructure can or should be forced on a community. “Some companies did it right, and some didn’t,” he said. “It’s really all about attaining your social licence to operate.”
Wind turbine technology is attractive because it can generate electrical power without producing emissions that pollute the air or contribute to climate change. But integrating wind power into existing electricity systems poses various challenges. One such challenge is illustrated using the following charts, which show how demand and supply were balanced on one day in 2012 in Ontario.
illustrates how the demand for electricity (the system load) varies up and down throughout the day. The level below which the load rarely drops is the baseload, supplied by power plants that produce electricity at a constant rate. Nuclear reactors supply the majority of baseload demand in Ontario, supplemented by some significant hydropower capacity (i.e., dams) and natural gas-fired power plants. Layered on top of the baseload is the load-following supply from power plants designed to ramp output up or down as needed to meet the varying demand. Last on the stack is wind, the output from which is neither steady nor artificially variable – its output is naturally variable according to the weather.
places wind at the bottom of the stack. This reflects general Ontario policy to use all available wind power at all times. Also, Chart 2 uses a logarithmic plot, which visually exaggerates the share of wind power. This helps us to see how wind output increased when demand decreased. This mismatch between system demand and wind power supply means that, as the number of wind turbines increase, additional load-following sources (e.g., gas, dams) could be needed as standby solutions for when the wind doesn’t blow.
Thus, the excess of nominal power-generating capacity grows, costing money to build and to operate. Moreover, to maintain overall system reliability and stability, neighbouring jurisdictions may even be paid to take Ontario’s excess electricity, further driving up costs. That is why increasing the share of intermittent, renewable power must be considered with the whole system in mind. Capturing the full benefits of wind power requires system-wide changes – not simply more turbines!
By Patchen Barss