AN APPROACH TO GENERATE FLEXIBILITY IN ENGINEERING DESIGN OF SUSTAINABLE WASTE-TO-ENERGY SYSTEMS

Designing an engineering system that is sustainable both environmentally and economically is a challenging and emergent task. This paper considers embedding flexibility into the engineering design of an upcoming waste-to-energy (WTE) system as a mechanism to ensure better sustainability in long-term lifecycle. A methodology is proposed to identify valuable opportunities to embed flexibility as a way to deal pro-actively with uncertain waste and consumer patterns. The proposed methodology helps to limit the number of flexible design concepts that decision-makers have to consider and analyze in the initial design phase. Application of the proposed methodology is demonstrated through the analysis of novel WTE technology in Singapore based on anaerobic digestion. Result shows that the expected net present value (ENPV) of the flexible design provides a 38.6% improvement over the fixed rigid design in terms of economic lifecycle performance. This design is conducive of better economic sustainability via additional power generation, and better use of resources. Results also indicate that the flexible design can reduce downside risks and capitalize on upside opportunities significantly.