Προς δημοσίευση ως contribution to the book “Waste-to-Energy in Developing Countries and Transitional Economies”, accepted to be published by Springer – Verlag. Decisions under uncertainty in Municipal Solid Waste cogeneration investments Athanasios Tolis* 1 , Athanasios Rentizelas 2 , Konstantin Aravossis 3 , Ilias Tatsiopoulos 4 National Technical University of Athens, Iroon Polytechniou 9 Str., 15780, Athens, Greece School of Mechanical Engineering, Industrial Engineering Laboratory *1 Corresponding Author – Research Engineer 2 Research Engineer, 3 Lecturer, 4 The issue of Municipal Solid Waste (MSW) management is an ever increasing problem for all countries. Developed countries face the problem of dealing with very large amounts of MSW per capita, forcing them to develop new technologies and systems. On the other hand, countries with developing or transitional econo- mies may generate lower amounts of MSW per capita, but the rate of increase is high and the current practices of MSW management are not as advanced as those of developed countries. Therefore, countries with developing or transitional economies may benefit from adopting MSW management technologies used by developed economies. One aspect of MSW management in developed economies is the energy recovery from MSW. The advantages of this type of technologies are mainly the significantly reduced waste volume for landfilling, the reduction of total greenhouse gas emissions, the potential for generating electricity or co-generation of electricity and heat. Professor Abstract In this work, a comparative study of the most prominent co-generation technologies using MSW as a fuel source is presented, focusing on the evolution of their economical performance over time. An algorithm based on real-options has been applied for four technologies of MSW energy recovery: (1) incineration, (2) gasification, (3) landfill biogas exploitation using a pipeline system and (4) anae- robic digestion facilities. The financial contributors are identified and the impact of greenhouse gas trading is analyzed in terms of financial yields, considering landfil- ling as the baseline scenario. The greenhouse gas trading system presents an oppor- tunity for investing in environmentally friendly technologies for MSW energy re-