Among researchers from energy sciences and economics the topic of "Hydrogen as Energy Carrier" is being hotly debated. On the one hand there will be enthusiastic visions of the hydrogen economy, bolstering hydrogen along with renewable energy sources as the prime direction for future development both regarding environmental protection (specifically the ban on green house gas emissions) as well as security of supply. On the other hand one will find far more sceptical estimations, at best viewing hydrogen as marginal energy source with poor qualities in the competitive mass energy market.In this project it was aimed to provide a close-up view of the economic rationale in the discussion of the hydrogen economy. This had to concern for one the spectrum of forecasted technological and cost developments in order to delimit their variability to a probable range. Even more so, however, the conditions determining the increased usage of hydrogen as part of economically sound environmental policy is a valid option.