Laboratory for Manufacturing and Sustainability

The greenhouse gas return on investment (GROI) metric is introduced as a compliment to the energy return on investment (EROI). Unlike EROI, GROI accounts for the life cycle energy mix, the efficiency, circularity, and supply chain of energy distribution, and the energy offset by a new energy installation. The average greenhouse gas emissions of labor and electricity are calculated for multiple countries to be used in GROI calculations. GROI is applied to a case study of SolFocus Inc. solar panels, and the potential extension of GROI methodology to a modified EROI and to decision making beyond energy is discussed.