INFLUENCE OF LEGISLATIVE CONDITIONED CHANGES IN WASTE MANAGEMENT ON ECONOMIC VIABILITY OF MSW-FUELLED DISTRICT HEATING SYSTEM - CASE STUDY

District heating systems represents one of the ways by which the European Union is trying to reach set goals in energy efficiency and security field. These systems allow the use of different energy sources including local energy sources such as waste and biomass. This paper provides economic viability assessment of using these fuels in the district heating system. Economic evaluation is based on regression analysis from data of existing plants and on the locally dependent data. Some of parameters that are dependent of local parameters are price and available fuel quantity, therefore these values are separately modelled; biomass as a function of location of the plant while municipal waste as a function of location and the time changes in waste quantity and composition which depend of socioeconomic trends and legislation. This methodology is applied on the case of district heating plants in the City of Zagreb where internal rates of return are calculated for four considered scenarios. Results indicate that waste powered plant can improve its profitability by co-combusting other local wastes while economic viability is achieved by introduction of region wide waste management system. Reducing plant capacity, based on prognosis of waste generation, showed that these plants can be competitive with biomass plants.