Organic energy could only offset 50% of the energy consumption of a WWTP in China.
About 1/5 of the effluent could supply a net thermal energy of 0.26 kWh/(m3 °C) via WSHP.
Photovoltaic technology is not economic albeit supplying 10% of the energy consumption.
Organic plus thermal energy could realize the goal of WWTPs towards carbon neutrality.