This paper presents a discussion of "A novel meta-heuristic optimization methodology for solving various types of economic dispatch problem" Fesanghary et al. "Energy" 34 (2009) 757-766. The discussed paper presented economic dispatch problem by experimenting with six case studies considering 38, 13, 15, 6, and 10-unit test systems along with multi area economic dispatch (MAED) problem. However, in the reported results of case study 3 and 6, the total fuel cost calculations are different for the given generation schedule. In this discussion, clarification regarding cost calculation is presented. (C) 2012 Elsevier Ltd. All rights reserved.