Economic and environmental assessment of electricity generation using biogas and heat energy from municipal solid waste: A case study of Lesotho

This study examined the potential of electricity generation from biogas and heat energy arising from municipal solid waste (MSW) collected from the year 2021 to 2045 using anaerobic digestion (AD) and incineration (INC) technologies. The goal of this paper is to evaluate the economic and environmental benefits of implementing the aforementioned technologies in Lesotho. The environmental impact was assessed by using the life cycle assessment strategy based on global warming potential for three scenarios, while the economic assessment was carried out by using the net present value (NPV), levelized cost of energy (LCOE) and total life cycle cost. The key findings show that, over 25 years (2021-2045), MSW generation will range from 185.855 to 513.587 kilotons. The methane yield for the duration of the project for AD technology is 44.67-126.56 thousand cubic meters per year. Moreover, the electricity generation will range from 0.336-0.887 GWh for AD technology and 17.15-45.34 GWh for INC technology. Economically, the results demonstrated that the two waste-to-energy technologies are viable, as evidenced by their positive NPV. The NPV for AD was about USD 0.514 million, and that for INC technology was USD 339.65 million. AD and INC have LCOEs of 0.029 and 0.0023 USD/kWh, respectively. The findings demonstrate that AD can minimize the potential for global warming by 95%, signifying a huge environmental advantage. This paper serves to provide the government, as well as the investors, with current and trustworthy information on waste- to-energy technologies in terms of costs, execution and worldwide effect, which could aid optimal decision-making in waste-to-energy projects in Lesotho.