Multi-criteria decision based waste to energy technology selection using entropy-weighted TOPSIS technique: The case study of Lagos, Nigeria

Abstract Selection of the most appropriate waste-to-energy technologies for distributed electricity generation is a complex and multi-criteria decision problem as it involves trade-off among conflicting criteria which have to be considered simultaneously. In this study, the Technique for Order of Preference by Similarity to an Ideal Solution (TOPSIS) with Entropy Weighted method is applied to select the optimal technology among the waste -to -energy technological options using the waste stream of Lagos, Nigeria. The results presented show that anaerobic digestion has been the best waste to energy technology solution for electricity generation in Lagos, followed by pyrolysis while incineration is seen as the worst preferred option of choice for energy generation applicability in standalone model. In order to maximally extract energy from waste in a sustainable, economical, and environmentally friendly manner, an integrated application of waste-to-energy technologies is also explored. It is found that the hybrid of anaerobic digestion, landfill gas recovery and pyrolysis give the most favourable results in terms of environmental benefits and electricity generation potential. It is also revealed that incineration technology either in the standalone or in the hybrid form is completely discouraged from being implemented in Lagos basically due to its high investment, operation and maintenance costs as well as its discouraging environmental image. Although, the case study in this paper is that of Lagos, Nigeria but the methodology presented could be used for any cosmopolitan city around the world.