Estimates of Renewable Energy Recovery from Biogas in Residential Buildings: Economic Feasibility Analysis

Abstract

Increasing of energy demand and climate change have hampered sustainable development. This article aimed to study the potential of biogas recovery for energy generation from compact wastewater treatment plants in buildings. Three buildings were selected and an economic feasibility analysis was carried out. The net present value (NPV) was positive and the economic internal rate of return (EIRR) was higher than the minimum attractive rate in five of six cases, showing that energy savings were sufficient to cover implementation, operation, and maintenance costs, with two to four years of payback time for biogas structures. The anaerobic reactor was responsible for the main expenditure, which indicates the importance of developing low-cost and compact units for decentralized wastewater treatment. Finally, the results indicate that biogas may be a promising and viable energy source in residential buildings.