INTERNATIONAL JOURNAL OF ENERGY RESEARCH Int. J. Energy Res. 2004; 28:769–784 (DOI: 10.1002/er.992) A modularized framework for solving an economic– environmental power generation mix problem Haoxiang Xia 1 , Michihisa Koyama 2 , Geoff Leyland 3 and Steven Kraines 2,n,y 1 Institute of Systems Engineering, Dalian University of Technology, Dalian 116024, China 2 Department of Chemical System Engineering, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan 3 Department of Engineering Science, University of Auckland, New Zealand SUMMARY This paper presents a modularized simulation modelling framework for evaluating the impacts on economic cost and CO 2 emissions resulting from the introduction of a solid oxide fuel cell (SOFC) system into the existing mix of centralized power generation technologies in Japan. The framework is comprised of three parts: a dual-objective linear programming model that solves the generation best-mix problem for the existing power generation technologies; a nonlinear SOFC system model in which the economic cost and CO 2 emissions by the SOFC system can be calculated; and the Queuing Multi-Objective Optimizer (QMOO), a multi-objective evolutionary algorithm (MOEA) developed at the EPFL in Switzerland as the overall optimizer of the combined power supply system. Thus, the framework integrates an evolutionary algorithm that is more suitable for handling nonlinearities with a calculus-based method that is more efficient in solving linear programming problems. Simulation experiments show that the framework is successful in solving the stated problem. Moreover, the three components of the modularized framework can be interconnected through a platform-independent model integration environment. As a result, the framework is flexible and scalable, and can potentially be modified and/or integrated with other models to study more complex problems. Copyright # 2004 John Wiley & Sons, Ltd. KEY WORDS: modularized framework; power generation mix problem; linear programming; MOEA 1. INTRODUCTION Power system planning is a complex problem with many aspects that must be considered. To alleviate its complexity, power system planners usually divide the overall problem of planning a power system into several sub-problems such as power expansion planning, operational power dispatch, load forecasting and network planning (Wang and McDonald, 1994 and Wood and Wollenberg, 1996). These sub-problems are then solved separately. Received 23 July 2003 Accepted 22 September 2003 Copyright # 2004 John Wiley & Sons, Ltd. y E-mail: steven@prosys.t.u-tokyo.ac.jp Contract grant sponsor: The Japanese Ministry of Education, Culture, Sports, Science and Technology under the ‘‘Grant-in-Aid for the Development of Innovative Technology’’; contract grant no: 12303 Contract grant sponsor: New Energy and Industrial Technology Development Organization (NEDO) of Japan; contract/grant no: Project Id. 01B62010d Contract grant sponsor: Alliance of Global Sustainability (AGS) n Correspondence to S. Kraines, Department of Chemical System Engineering, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.