Optimization of use of waste in the future energy system

Alternative uses of waste for energy production become increasingly interesting when considered from two perspectives, that of waste management and the energy system perspective. This paper presents the results of an enquiry into the use of waste in a future energy system. The analysis was performed using the energy system analysis model, Balmorel. The study is focused on Germany and the Nordic countries and demonstrates the optimization of both investments and production within the energy systems. The results present cost optimization excluding taxation concerning the use of waste for energy production in Denmark in a 2025 scenario with 48% renewable energy. Investments in a range of waste conversion technologies are facilitated, including waste incineration, co-combustion with coal, anaerobic digestion, and gasification. The most economically feasible solutions are found to be incineration of mixed waste, anaerobic digestion of organic waste, and gasification of part of the potential RDF (refuse derived fuel) for CHP (combined heat and power) production, while the remaining part is co-combusted with coal. Co-combustion mainly takes place in new coal-fired power plants, allowing investments to increase in comparison with a situation where only investments in waste incineration are allowed.

► The analysis is based on hourly chronological time steps, thereby taking dynamic properties of the energy system into account. ► The system analyzed includes both the heat and the electricity market, which is important when analyzing e.g. CHP technologies. ► The surrounding countries, which form part of the same electricity market, are included in the analysis. ► New innovative Waste-to-Energy production plants have been modeled to allow for a more efficient and flexible use of waste. ► The analysis includes economical optimization of operation and of investments in production and transmission of both electricity and heat.