Turbine towers over Auckland

A small wind turbine near the top of the Sky Tower is testing the way for similar turbines that could be used on roofs around the city.

The 1.5kw Swift turbines, which are being tested by electricity distribution company Vector, could provide between 2000 and 3000 kilowatt-hours of electricity a year - about a quarter of the average household's annual needs. The object is to see how the turbines, which weigh about 50kg, perform in an urban environment.

They are designed for the relatively low-speed and turbulent winds at rooftop level.

If the trial is successful the price of the turbines could, with big orders, reduce to about $8000.