Waste-to-Energy Facility Planning Supported by Stochastic Programming - Part II Model Development and Application

This paper deals with the development and presentation of the use of computational optimization tool for the conceptual planning of facilities in the field of waste-to-energy (WTE). Decision about individual facility parameters includes in particular the determination of suitable capacity and selection of appropriate heat recovery system according to heat released utilization strategy (i.e. either only electricity production or combined heat and power if feasible). The main goal is to ensure the economic feasibility of the project. An optimization tool that was created in the system GAMS (General Algebraic Modelling System) was developed for this purpose and is introduced in this paper. Realization of a new plant from the initial considerations to its full operation is a long-term process with duration at minimum 5 to 7 years. The erection is then followed by operational phase exceeding 20 years. At the beginning of the project (preparation of implementation phase) when important decisions related to the technology selection are made, the future development of many parameters affecting project sustainability are not clear. The developed tool takes these aspects into account by implementing elements of stochastic programming that allow this uncertainty and randomness to be reflected in optimization problems and, hence, proposed solution. In the article, a brief theory related to uncertainties (approach wait and see and/or here and now, definitions and use of scenarios), is given by first, followed by a description of a mathematical problem and demonstration of using tools through the case study.