Visitors driving along Cedar Lake Road in Round Lake, Ill. — a 6,000-person community about an hour north of Chicago — may be puzzled by the sight of a wiry metal installation on the roof of the modest white brick law offices of Magee, Negele & Associates. Is it industrial sculpture? Only in a sense. It’s actually a wind turbine.

The law firm’s roof is a testing location for Aerotecture International Inc., which provides consulting, design and installation of renewable energy sources.