Economic analysis of investment projects in renewable energies for a sustainable energy system

This paper suggests an economic assessment of renewable energies (RE) projects. The analysis is related to the case study of two RE projects. This study involves energy recovery from sewage sludge through two technologies (a) anaerobic digestion with biogas utilisation in combined heat and power (CHP) system for the first project and (b) gasification with biogas utilisation in CHP system for the second project. In this context, the objective is to assess the energy and economic balance of these two technologies in terms of energy, cost and environmental impact. The basic idea of this paper is to emphasise the necessity of establishing a mixed approach: the approach of economic engineering. Our results raised the importance of performing an economic assessment based on life cycle analysis, which allows us to evaluate all costs and benefits throughout the system’s life cycle. Copyright © 2018 Inderscience Enterprises Ltd.