An energy system using a microgrid was examined in this work. The motivations for this study are to promote green energy usage, discuss concerns regarding energy supply during disasters, and improve the efficacy of waste heat usage. To create a society based on clean hydrogen energy, this paper studied the use of a microgrid to supply energy to six houses in a cold region. The proposed microgrid consisted of photovoltaics, a water electrolyzer, a fuel cell, and a heat pump; furthermore, this microgrid was not accompanied by any external energy supply. In this paper, the optimized calculation results obtained from the genetic algorithm (GA) were compared between a system operated using one set of large capacity equipment (a concentrated system) and a system operated using two or more pieces of distributed small-capacity equipment (a distributed system). From this comparison, the operation efficiency of each set of equipment was characterized using the difference in the load factor of the fuel cell and that of the water electrolyzer of each system. Moreover, the optimal capacities of the solar cell, fuel cells, water electrolyzers, and heat pumps while operating an energy-independent microgrid with the concentrated system and the distributed system were presented. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.