Maximising renewable gas export opportunities at wastewater treatment plants through the integration of alternate energy generation and storage options

Sci Total Environ. 2020 Nov 10:742:140580. doi: 10.1016/j.scitotenv.2020.140580. Epub 2020 Jul 1.

Abstract

Decarbonisation of all sectors of the economy is required if humanity will meet the Paris Agreement. Emissions from the electricity sector have fallen considerably in the past 10 years, however, other sectors of the economy have not been able to keep pace due to their reliance on natural gas. Wastewater treatment plants are in a unique position to help these sectors as they are able to generate renewable biogas which can be used as a substitute for natural gas. Currently, some wastewater treatment plants burn their biogas to meet onsite energy requirements; however, there is growing scepticism in the industry as to whether this is the most effective use of this resource. The current study investigates whether it would be economically and environmentally beneficial for these wastewater treatment plants to sell their biogas and generate energy through other means. To this end a case study assessment of a plant in Adelaide, South Australia was undertaken. Results showed that all studied cases resulted in significant economic and environmental gains over the traditional biogas-only system, suggesting that there is considerable potential for future changes to the way wastewater treatment plant are operated to realise their full potential as urban resource recovery facilities.

Keywords: Biogas generation; Electrolyser; Renewables integration; Wastewater treatment plants.