The Overall Energy Balance of a Hydrogen Bus in Berkeley

by Tadeusz W. Patzek, K. Kappler, A. F. Dahmubed, S. C. Moses, D.-K. Chen, H. N. Handa, J. W. Heng, M. Q. Ho, D. C. Kellogg, E. K. Negroni, I. P. Nicholson, S. L. Orozco, J. M. Prendergast, T. A. Pritchard, K. N. Vo, A. R. Wysong
Year: 2004


Patzek, T. W. and CE24 Freshmen, "The Overall Energy Balance of a Hydrogen Bus in Berkeley," rejected by Science, Berkeley, CA, May 2004.


Hydrogen fuel cell buses are being tested in several cities in California as a clean, environmentally-friendly alternative to diesel buses. In Berkeley, a hydrogen bus system consists of grid electricity, electrolyzer, hydrogen compressor, hydrogen tanks, and a bus propelled by electrical motors driven by a 60 kW hydrogen fuel cell stack and a 600V auxiliary battery. We show that the overall energy efficiency of this system is 2-3 times lower than that of a diesel bus. The prototype hydrogen bus generates elsewhere 2-3 times the CO2 emissions, and several times the NOx and SO2 emissions of the clean diesel bus equipped with a catalyzed soot filter, and it costs 18 times more.