Small-scale wind turbines, designed for residential, rural or agricultural use, represent a growing segment of the renewable energy market, but still account for a tiny fraction of the overall output from wind energy facilities. As of 2008, small-scale turbines in Canada generated a total of 5.5MW. The market for this type of equipment was about $11 million in 2007.
They are very different from utility-scale turbines in terms of design and scale. Most are well under 25 metres high, and have rapidly-rotating blades which sit atop trestle-style towers. Some are even erected on rooftops.
Such turbines tend to be used for help in generating electricity in so-called off-grid locations, such as cottages situated in remote areas. In other applications, they may generate power for pumping systems on large farms. Small turbines can also be used in jurisdictions that allow “net metering” – i.e., the owner is allowed to sell the turbine’s electricity back to the local utility.
Northern communities are among the most active markets for small wind energy in Canada. Quebec’s Wind Energy Technocentre recommends the adoption of policies and incentives for northern communities to establish smaller-scale wind turbines. These incentives include introducing a “regionally indexed tax credit for annual kilowatt-hour production”. CanWEA’s proposed projects for small-scale wind farms in remote communities would provide nearly 10% of the electricity demand, cutting out up to 300 million litres of imported diesel fuel every year .
Generally, a small-scale turbine on its own will not provide enough energy to satisfy the power usage for a home in an off-grid location. In such situations, the turbine is just one component of an integrated renewable energy system that may also include solar panels, geothermal heating, and back-up diesel generators.
This animation illustrates how wind form. It depicts the movement of air upwards as it is heated, and cooler air moving in to fill the void.