This paper uses a series of interviews to investigate how municipal planners in three Canadian provinces (Nova Scotia, Quebec, and Ontario) influence setbacks that regulate appropriate locations for wind turbines. Setbacks are provisions in local land use policies that dictate required separation distances between wind turbines and other land uses. Results of the study indicate that planners are not using a consistent method to ascertain appropriate distances and are often constrained by a lack of experience, resources, and expertise. These findings have important implications for wind energy regulation. Setbacks are intended to reasonably protect the public from the impacts of wind turbines, while allowing for some development. Municipalities in Canada may be best placed to consider local impacts of wind power, but the challenges identified raise concerns about potential arbitrariness. Setbacks that are unjustifiably high can unnecessarily close off territory and limit the ability to reach renewable energy targets. Taking regulatory power away from municipalities, as has happened in Ontario, can facilitate achievement of provincial targets, but may also increase opposition to projects at the local level. (C) 2011 Elsevier Ltd. All rights reserved.