Greenfield’s Energy Park is a gem in the center of town. Main Street is all bustle and work, but a short stroll down Miles Street takes you to the peaceful gardens and shade of a town park created in 1999. Sandy Thomas was the director of the Northeast Sustainability Energy Association (NESEA) housed in the former railroad switch house building in the blighted area left by the demolition of the railroad station. In 1999 the town had a…