As opponents of the proposed backyard wind turbine at 70 Iona St., we can assure readers that it was not "fear of the unknown" that led to our opposition to the installation. It was concern about the known.

The Ontario Municipal Board decision focused on planning issues and the applicant as a result failed on all four required tests for the minor variance Graham Findlay sought.

But two larger issues emerged in the OMB hearing: the effectiveness of small residential wind turbines and their regulation.

A big elephant in the back yard for us was that small wind turbines in a poor wind regime such as residential Ottawa are ineffective. Grade school arithmetic is all you need.

Assuming this 500-watt turbine ran at full output, non-stop, day in and day out, year in and year out, it would take about 20 to 30 years to pay back its cost.

But according to the manufacturer, to generate 500 watts requires a wind speed of about 60 kilometres per hour, that is at the lower end of gale force winds.

The reality is in the average annual Ottawa wind regime of four metres per second the manufacturer says it will only produce 100 kilowatt hours of power per year.

It will produce zero renewable energy in its lifetime since it will be kept busy paying for itself.

A recent study of small wind turbines by the U.K. Carbon Trust makes it clear that a small wind turbine in city residential areas will never in its lifetime generate enough power to offset their carbon footprint. They will actually harm the environment.

The other major issue that emerged was the lack of regulation of small wind turbines in urban areas, as distinguished from industrial wind farms that are regulated at all levels of government. Safety is the issue here.

The City of Ottawa has no inspection protocols for small wind turbine installation or maintenance, and therefore no inspectors.

Only in the past two years have standardized regulations for small turbines been drawn up by an independent body in Canada, and so far as we know they have not been adopted by any level of government.

"Small" wind turbine means neither green nor safe, as things stand. But as a result of the OMB decision, the city's new zoning bylaw on height and location of residential wind turbines thankfully remains intact.