08/29/2007 Clearing the Air on Wind Energy
Article reprinted in the Winnipeg Free Press and London Free Press
By Robert Hornung
Canada’s wind energy industry is experiencing remarkable growth. This is a good thing, since wind energy is an important part of a clean, renewable and sustainable energy future. Wind energy produces no air pollution, contributing to better air quality for everyone; and also produces no greenhouse gas emissions, making it an important component of our efforts to address climate change. Just as importantly, wind energy is helping to revitalize rural economies, resulting in new investment, tax revenues and jobs for communities that have often been hard hit by declines in traditional agriculture and resource industries.
The rapid increase in the number of projects both in operation and under development in Canada has led to increased public discussion about wind energy: What are its impacts? What are its benefits? What role will it play in Canada’s energy future? These questions, and the concerns they raise, are to be expected with any technology that is relatively new to the political, economic and social landscape of the country. Unfortunately, some of the current discussion around these questions reflects either a lack of information, or in some cases, misinformation about wind energy. I’d like to take this opportunity to examine some of these issues and provide perspective on what experience has shown us with wind energy in Canada and around the world.
Impacts on Wildlife: Wind turbines can potentially have impacts on birds and bats by either changing their natural habitat or through collisions with the turbines themselves. In reality, wind turbines have a much smaller impact on birds and bats than buildings, house cats or the climatic changes that are already having an impact on many bird habitats.
It is worth noting that the U.S.-based National Audubon Society recently announced its support for well-sited wind projects, stating “On balance, Audubon strongly supports wind power as a clean alternative energy source that reduces the threat of global warming” and indicating that “each project has a unique set of circumstances and should be evaluated on its own merits.”
The key is proper siting. Fortunately, modern wind farms must participate in, and get approval from rigorous Federal and Provincial environmental assessment processes that ensure that wind farms are sited properly from a wildlife perspective.
Safety: Some have argued that they pose a safety risk if they were to fall over or if turbine blades were to shed pieces of ice in the winter. It is important to note that, like buildings and other structures, wind turbines are built to meet the rigorous requirements set out by provincial building codes and international safety standards. And while wind turbines blades can potentially throw ice, modern operating practice makes this highly unlikely. Experience indicates that at typical setback distances between turbines and dwellings, the chance of being struck by ice are almost infinitely small.
Sound: Wind turbines do produce audible sound, usually characterized by the “swoosh” of blades as the turbine rotates. The actual sound level is influenced by many factors including the type and number of turbines, the wind speed, and the surrounding topography.
Fortunately, wind energy projects, like any development near public spaces, must meet regulatory requirements to ensure that sound levels do not adversely affect surrounding populations and homeowners. Experience around the world indicates that acceptable sound levels can be achieved at distances much less than the one kilometer setback suggested by some. In fact, in most cases the sound of the turbine is masked by background sounds that also tend to increase with an increase in wind (for example, the rustling of leaves in the trees).
Infrasound: There has been some discussion about potential impacts associated with sound below the human threshold for hearing, or infrasound. A review of reputable, peer-reviewed studies on the subject indicates that while wind turbines do create infrasound, the levels produced are often similar to the ambient levels prevalent in the natural environment and below levels known to have an impact on human health. These studies unanimously conclude that there is no evidence of adverse health effects caused by this infrasound.
Compatibility with Agricultural Practices: Wind turbines are, in fact, very compatible with agricultural practices, and this has led companies such as John Deere to actively assist farmers in developing wind as a way of diversifying their incomes. Although a wind farm can cover a wide area, the turbines themselves generally only occupy five percent of the land area, leaving the remaining 95% for conventional uses. In fact, farmers routinely graze cattle or farm crops right up to the base of the turbines. And while some have expressed concern over potential conflicts between wind turbines and crop dusters, experience has shown that it is possible for the two to operate side by side.
Reliability: The energy production of a single wind turbine varies (naturally) with wind speed. Unfortunately, this has led some to believe that wind is an “intermittent” energy source that we cannot count on as part of a reliable electricity system. But experience has shown that the energy production of several wind farms spread over a wide geographic area is actually quite even, simply because the wind does not start and stop blowing at the same time in different locations. In fact, electric utilities around the world have discovered that wind is not only easy to integrate into their existing grids, but can actually contribute to the overall reliability. As a result, countries like Denmark, Spain and Germany are now able to obtain 20%, 8% and 6% (respectively) of their electricity from wind energy. All of them are working to increase those numbers.
Economics: Wind energy is already cost-effective in comparison with some forms of conventional power generation. In fact, there are now several examples in the United States where people who signed up for programs to pay a premium for wind energy are now paying less than the majority of customers who decided to stick with conventional energy sources. And wind makes an important contribution to the economy, too: the Canadian wind industry now contributes over $1.5 billion to Canada’s GDP, an amount that is growing every year.
Polling numbers have consistently shown overwhelming support for wind energy development in Canada. In fact, data has shown that acceptability increases with proximity to operating wind turbines. Federal and Provincial Governments have taken important steps to facilitate wind energy deployment and have now set targets that will see Canada’s installed wind capacity increase at least six-fold in the next eight years. All of this will bring important social, economic and environmental benefits to Canada.
Public discussion of wind energy will and must continue. It is important, however, that such discussion be based on well-informed, peer-reviewed facts. We must also never lose sight of our collective global responsibility in these discussions - to not just think of our own backyards, but future backyards - those of our children. And their children, too.
Robert Hornung is President of the Canadian Wind Energy Association (www.canwea.ca)