Trenton Forging of Trenton, Mich., discovered an innovative way to utilize the unused energy from its manufacturing processes. The company, a producer of custom impression-die forgings, created a rooftop greenhouse that uses the natural byproduct to heat water that feeds into the greenhouse. The 1,600-foot structure takes a previously unused resource and transforms it into a harvest of over 1,400 plants, which include lettuce, spinach, herbs, tomatoes and flowers. “It only makes sense to find a renewable use for unused energy. We’re excited about continuing to move forward in our efforts to enhance the environment,” said David Moxlow, Trenton Forging’s president.