Life cycle GHG emissions for FCVS in Japan

Fuel cell vehicles offer an opportunity to reduce greenhouse gas emissions because of their higher efficiency than internal combustion engines. It is important however, to analyse these vehicles on a full life cycle basis. These life cycle analyses need to be done for specific regions since the energy pathways can be different from one region to the next. There have been a number of studies published recently that have considered the fuel cell life cycle greenhouse gas emissions in a North American or European context. The energy pathways considered in these studies are not directly applicable to Japan. Some of the major differences in the Japanese energy pathways include the fact that almost all energy is imported and in the case of natural gas it is liquefied before transport to Japan and then vapourized before use. This extra step of liquefying the gas affects all natural gas pathways in Japan. The results of this study of the Japanese energy pathways are quite different from the typical results for North America. Whereas most studies show that natural gas reformed to hydrogen for use in a fuel cell vehicle produces the lowest greenhouse gas emissions with a reduction in emissions of 45 to 50% compared to the gasoline internal combustion engine, in Japan the reduction is only on the order of 31% and the methanol reformed on board the vehicle option produces greenhouse gas emission reductions of 41%. Methanol reformed to hydrogen off board a vehicle, results in a 38% reduction. Hydrogen produced by electrolysis in Japan will result in an increase in greenhouse gas emissions when used in fuel cell vehicles.