Thermoeconomics can play a key role in the analysis of eco-industrial parks because it provides a systemic approach and, by using exergy, expresses matter and energy flows in the same physical units. Besides methodologies developed for thermal systems analysis, diagnosis and optimization, application of thermoeconomics to industrial symbiosis requires the development of new methods such as those presented here. First, two decomposition strategies for exergy costs are proposed (according to: (i) irreversibility and (ii) origin of resources). Then, a fuel impact approach for locating and quantifying the origin of resources savings due to integration is presented. A simplified version of the Kalundborg eco-industrial park is used as a test-bench for the presented methodologies. (C) 2013 Elsevier Ltd. All rights reserved.