Solar Cogeneration – A New Renewable Technology for Water and Wastewater Treatment Plants

This paper explores different types of solar power systems, explains how solar cogeneration systems work and examines how Water Treatment Plants (WTPs) and Water Resource Recovery Facilities (WRRFs) could potentially utilize solar heat and power to improve their environmental sustainability and be financially beneficial. Through an objective feasibility analysis we evaluate three possible solar cogeneration applications using the Santa Rosa Laguna Treatment Plant in Santa Rosa, California as an example location. The analysis presents calculated system sizes, needed land, electrical power and thermal energy performance estimates, and a 25-year net present value (NPV). The results show that all three alternatives provide a significantly positive 25-year NPV but do require large amounts of land for siting such systems. Based on these findings we believe solar cogeneration systems are a viable and cost effective form of renewable energy and should be considered alongside traditional onsite energy generation alternatives.