Recovering energy from waste in Sweden -: a systems engineering study

The possibilities for recovering energy from waste in Sweden around the year 2010 are explored in this paper. To capture the issue from the perspectives of both the waste management and the district heating systems, separate systems engineering studies are performed for each. Four questions are explored: (1) Is recovering energy from waste economic from a waste management system perspective?; (2) Is there a significant untapped energy resource in the form of waste in Sweden?; (3) Is recovering energy from waste economic from a district heating system perspective?; and (4) What are the global warming implications of recovering energy from waste? The results show that recovering energy from waste is part of all solutions studied, since energy recovery is necessary in order to fulfil the coming ban on landfilling of combustible and organic waste. However, the optimal quantity of energy to recover from waste differs considerably depending on the system perspective taken. From a waste management point of view, the economically optimal solution is to combine heat recovery with a high level of materials recovery. In this case, the quantity of heat recovered is close to the present Swedish level. From a district heating point of view, the potential could be 2-6 times larger. In terms of global warming implications, the preferable solution is to combine materials recovery and combined heat and power from waste. By bringing both the waste management and the district heating systems into focus, knowledge has been gained. The district heating study reveals a future market for heat recovery from waste that could be significantly larger than today. The waste management study points out that new policy instruments will be introduced in Swedish waste management that could direct waste towards increased energy recovery if the materials recovery sector does not develop strongly. These potential changes would have been more difficult to foresee had one system or the other been restricted to consideration as part of the system environment. (C) 2002 Elsevier Science B.V. All rights reserved.