Ontario’s environment ministry has released proposed siting guidelines for offshore wind turbines that set a minimum distance of 5km (3.1 miles) from shore.  The rules, which are now open for public comment, will be subject to public hearings in the fall. Ontario does not have ocean frontage; the rules are meant to govern wind farms planned for the Great Lakes.

The proposed standard would undermine some proposed wind farms, which are aiming to be 2-4km from shore.  It is likely that the proposal would greatly minimize the visual impact of turbines, and would may also reduce sound impacts to an acceptable level.  As noted in this brief essay, sound travels very easily over water, so that typical onshore setbacks could be insufficient for offshore sites.  Some reports from near the Wolfe Island wind farm (at the end of Lake Ontario, near the start of the St. Lawrence Seaway) suggest they are often quite audible from two miles, and occasionally somewhat audible at five to seven miles.  While there is often an assumption that wave sounds will easily drown out distant turbines, it’s likely that people living somewhat inland from the shoreline in otherwise very quiet rural areas would be the most affected by offshore turbine sounds.