in order to achieve a hydrogen economy, developing widespread hydrogen supply systems are vitally important. A large number of technological options exist and are still in development for hydrogen production, storage, distribution..., which cause various pathways for supplying hydrogen. Besides the technical factors, there are other effective parameters such as cost, operability, reliability, environmental impacts, safety and social implications that should be considered when assessing the different pathways as optimal and viable long-term alternatives. To aid this decision-making process, we have developed a generic optimization-based model for the long-range energy planning and design of future hydrogen supply systems. By applying Linear Dynamic Programming techniques, the model is capable of identifying optimal investment strategies and integrated supply system configurations from the many alternatives. Also, the environmental impacts of hydrogen supply system can be evaluated through scenario analysis. The features and capabilities of the model are illustrated through application to Iran as a case study. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.