For the introduction of a hydrogen economy one of the most relevant questions is: what are the suitable feedstocks and production technologies for hydrogen, which is a secondary energy carrier, taking into account the manifold objectives of hydrogen introduction: the cost-effective substitution of oil, increasing the security of energy supply, and reducing CO2 and other emissions? This study focuses on constructing a hydrogen infrastructure in Europe by 2030. Several hydrogen technologies and their integration into an infrastructure system, including the production, transport and distribution of hydrogen, are analysed on the basis of energy chain calculations and expert judgements and consistent scenarios are developed. It can be shown that under economic and CO2-reduction objectives, the steam reforming of gas, followed by coal gasification and, to a limited extent, the electrolysis of electricity from renewable energy carriers are the most promising hydrogen production options in this first phase for developing a hydrogen infrastructure. These options result in a significant level of CO2-reduction. However, the total cost of the infrastructure will account for 0.3% of EU-25 GDP in 2030. This shows the extent of the challenge involved in constructing a hydrogen infrastructure. (c) 2006 Elsevier Ltd. All rights reserved.