Engineering design in power generation or conversion has typically focused on minimizing exergy losses (entropy gains), or maximizing economic returns. Both entropy minimization and profit maximization are readily obtainable and acceptable objective criteria for design of thermodynamic processes. However, alternative criteria are imaginable. This research presents a framework for considering minimal environmental impact or maximum renewability as alternative design criteria. In the environmental case, fuel source is based upon an exergetic environmental metric called pollution potential. In the case of renewability, a life-cycle metric describing the replacement time frame of the fuel source is employed. When coupled, the two metrics together partially assess the overall sustainability of the design.