The development of a bioethanol steam reforming system (FBSR) is considered as a means of distributing energy using PEM fuel cells. Small-scale solar collectors (collection areas on the order of several m(2)) are installed in a house as a method for applying the FBSR. However, the temperature distribution of a reforming catalyst fluctuates under conditions of unstable solar insolation. Therefore, heat transfer analysis applied in reforming the catalyst layer of the reactor and the temperature distribution and transient response characteristics of the gas composition of the process were investigated. As a case study, meteorological data for representative days in March and August in Sapporo, Japan were recorded, and the hydrogen production speed, power generation output and amount of electricity purchased were analyzed. The results showed that although fluctuations in solar insolation affected the efficiency of the FBSR, the average efficiency of each representative day exceeded 40%. By installing two solar collectors, each with a collection area of 1 m(2), 21-25% of the average power demand of an individual house can be supplied. (C) 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.