According to the study by the Laboratory for Energy and the Environment (LFEE), hydrogen fuel cells for vehicles, even with aggressive research, will not be better than the diesel hybrid (a vehicle powered by a conventional engine supplemented by an electric motor) in terms of total energy use and greenhouse gas emissions by 2020. The results of the survey, led by Malcolm A. Weiss, LFEE senior research staff member, and John B. Heywood, the Sun Jae Professor of Mechanical Engineering and director of MIT’s Laboratory for 21st-Century Energy, are based on an assessment of a variety of engine and fuel technologies as they are likely to be in 2020, with intense research but no real “breakthroughs.” The study reports that the hydrogen fuel cell vehicle has low emissions and energy use on the road, but converting a hydrocarbon fuel such as natural gas or gasoline into hydrogen to fuel this vehicle uses substantial energy and emits greenhouse gases. “Ignoring the emissions and energy use involved in making and delivering the fuel and manufacturing the vehicle gives a misleading impression,” said Malcolm Weiss.
Researchers do not recommend stopping work on the hydrogen fuel cell. “If auto systems with significantly lower greenhouse gas emissions are required in say, 30 to 50 years, hydrogen is the only major fuel option identified to date,” stated John Heywood. Because the production of hydrogen must occur without making greenhouse gas emission, the hydrogen must come from a noncarbon source such as solar energy or from conventional fuels while sequestering the carbon emissions.
The assessment highlights the advantage of the hybrid, an efficient approach that combines an engine ( or possibly a fuel cell) with a battery and an electric motor. Continuing work on today’s gasoline engine and its fuel will bring major improvements by 2020, cutting energy use and emissions by a third, compared with today’s vehicles. Aggressive research on a hybrid with a diesel engine could yield a 2020 vehicle that is twice as efficient and half as polluting, according to the study.