Life cycle assessment of different hypotheses of hydrogen production for vehicle fuel cells fuelling

The aim of this study is to compare the environmental effects, through the Life Cycle Assessment approach, of three hydrogen production methods: methane steam reforming, water electrolysis fed by photovoltaic electricity, water electrolysis fed by mini-hydroelectric electricity. The assumptions are based on the "HBUS Firenze" project in progress in Florence (Italy) for the introduction of hydrogen minibuses in the city centre. The inventory of the,compared productive cycles has been performed using literature data and direct data obtained from the device manufactures. The impact analysis has been carried out using two methods, the Ecoindicator'95 and the Ecoindicator'99 also with the intention of qualitatively comparing the results. Besides the "basic option" an improvement has been proposed focusing on the weak points of the productive cycles. In particular concerning photovoltaic and mini-hydroelectric, the construction phase showed a high contribution to environmental load, so some improvements were proposed. The results of the basic option and the improved one have been compared. According to the initial assumptions and the proposed changes, the best option for hydrogen production has been highlighted.