Shaping the New Low-Energy WRRF: Strategies Based on Renewable Alternatives

New technologies are quickly re-shaping the energy intensity and operational costs of water resource recovery facilities (WRRFs). The penetration of affordable technologies embracing concepts as 1) energy storage, 2) renewable resources, and 3) energy efficiency (CHP, co-digestion) are impacting the costly traditional energy schemes in wastewater management. A model-based and validated with real-case studies was developed to quantify economically and environmentally the balance between the actual energy demand of a WRRF with potentially available renewable (or non- conventional) alternatives, while incorporating daily and seasonal site-specific variations together with existing energy tariff structures. The model provides validated estimates on the overall costs (i.e., Present Net Value) concerning the alternative deployment and the associated environmental impacts (CO2 eq. reduction) for each of the potential alternatives related to the studied plant. Four actual WRRFs were analyzed using the developed model resulting in the identification of strategies that could reduce operational costs and reduce CO2 emissions.