Energy and water autarky of wastewater treatment and power generation systems

The energy-water nexus of the water supply, wastewater treatment and power generation systems has been well discussed. It is very clear that one source cannot be produced or supplied without involving the other source. Since the two systems are intertwined with mutual needs, it is difficult to resolve the issues associated with them in isolation. However, combined solutions through integrated approaches may not be feasible in all situations. Therefore, it is important to consider the energy or water autarky (self-sufficiency) of these systems. If these systems can achieve autarky for the energy and water needs independently, such configurations can be considered sustainable. This review paper presents the energy and water needs for water supply, wastewater treatment, and power generation systems and critically examines the potential opportunities for achieving energy and water autarky in these systems. A detailed view of the water supply and wastewater treatment systems’ energy footprint was presented and similarly the water footprint of various power plants. Different approaches for achieving energy autarky in the wastewater treatment systems as well as approaches for water autarky in the power generation systems were discussed. It is imperative that future developments should consider an integrated design approach to improve the overall system autarky by communicating between the two individual systems, by considering synergistic energy-water production, by collaborating resources planning and energy-water infrastructure synergies supported by science and system-based natural resource policies and regulations.