The case for hydrogen

Feb. 9, 2009
This is a response to the letter from Thomas Wyman entitled “Hydrogen and thermodynamics.”

This is a response to the letter from Thomas Wyman entitled “Hydrogen and thermodynamics” (OGJ, Jan. 19, 2009, p. 14).

Mr. Wyman bemoans the fact that it takes more energy to make hydrogen than is contained in that hydrogen. True, but what about other energy carriers? It’s a good thing that this thinking didn’t prevail in the 18th century when inventors were developing a new energy carrier that could transmit large quantities of energy nearly instantaneously over long distances. This new energy carrier could economically power homes, factories, and buildings without producing any pollution. But there was a major roadblock: It would take two to three times more energy to generate this carrier than it contained.

Fortunately, the likes of Faraday, Tesla, Edison, Westinghouse, et al. were not impeded by this take on thermodynamics as they developed electricity as a practical energy carrier. Today a coal plant might produce electricity at 36% efficiency. Adding 8% loss in transmission, the overall efficiency might be 33%. Thus it takes over 300 MJ of coal to make 100 MJ of electricity. Advanced natural gas combined cycle power plants might reach 60% efficiency for a net 55% system efficiency, but it still takes more energy to make electricity than is embodied in that electricity. Is this justification to renounce electricity?

Hydrogen is routinely produced by reforming natural gas at 75% efficiency. It takes 133 MJ of natural gas to make 100 MJ of hydrogen. Given that a fuel cell vehicle burning hydrogen is at least twice as efficient as a conventional car burning natural gas, 100 MJ of natural gas converted to hydrogen will propel a fuel cell car 50% farther than that same 100 MJ of natural gas in a conventional car. Furthermore, the fuel cell vehicle will produce no urban air pollution, and hydrogen, like electricity, can be made from virtually any fuel.

C. E. (Sandy) Thomas, PhD
H2Gen Innovations Inc.
Alexandria, Va.