Economic and ecological assessment of photovoltaic systems for wastewater treatment plants in China

The number of wastewater treatment plants (WWTPs) in China is fast growing as the country's urbanization accelerates. WWTPs, part of the high-energy-consumption industry, must use a lot of energy in wastewater treatment. PV projects in WWTPs are viable solutions for energy conservation, but PV project investors, WWTP owners, and government authorities need to conduct rigorous economic and ecological assessments. This article examines the PV potential, financial feasibility, energy savings, and emission reduction effect of large-scale WWTPs in China using the cable-supported system. Furthermore, China's total PV power potential for urban WWTPs has been assessed at 5.6 GW for the first time. According to economic feasibility analysis, 26 of the 31 WWTP-PV projects in China's various regions are economically viable. Moreover, the WWTP-PV projects can assist WWTP in reducing carbon emissions by 10%–40%. Further sensitivity analysis reveals that practically all WWTP-PV projects will be viable in the future, assuming that certain solar resource requirements are met, and appropriate investment strategies are implemented. • China has a total PV power potential of 5.6 GW for urban WWTPs. • The economic feasibility analysis shows most WWTP-PV projects in China are viable. • The WWTP-PV project can help WWTP reduce carbon emissions by 10%–40%. • The PV potential of a WWTP is correlated with its planned wastewater treatment capacity.