A small-sized hydrogen gas-turbine originated from a light-weight car turbo-charger is selected as a practical candidate in constructing an alternative hydrogen energy system element and its energetic characteristic is experimentally examined. Additionally, the potential of alternative hydrogen energy systems including hydrogen gas-turbines are investigated from the standpoint of usage, regeneration, transportation, storage and of wasted heat reutilization including environmental load reduction. Some hydrogen energy schemes are also revealed in this paper.