Reuters: The idea of wind turbines churning out free electricity alongside every home and office building has appeal, judging by the throngs around “community wind” purveyors at a Chicago wind power convention this week. Darrin Russell of Southwest Windpower was inundated with questions during the Windpower 2009 convention where he explained the economics of the company’s workhorse 2.4 kilowatt Skystream turbine, which plugs into the local electrical grid. “It’s nice watching the …