As of midnight December 23, three of the four machines, which have just gone online, were synchronized with the electricity grid and producing power, Terry Murphy said.
The city's entire electricity needs were satisfied by wind energy for six hours overnight, Murphy said an achievement that exceeds the city's expectations for the turbines.
He said the city will be happy if it gets a third of its electricity annually from wind, on average.
Winter, with its fierce air currents, is the best time of year to create aeolian energy.
Construction began on the four 80-metre-high turbines over the summer in the city's St. Eleanors neighbourhood. Costing $30 million total, they are designed to generate 12 megawatts of power.
Some local residents ardently opposed the wind farm, saying it would cut into their property values, create noise and pose possible health risks.