Hydrogen fuel

In his letter to the editor, Len Farias states that to help achieve energy independence, hydrogen would be an ideal fuel for vehicles (C&EN, Sept. 25, page 8). The proposal to fuel vehicles with hydrogen instead of gasoline has gotten a lot of press: President Bush included it in his list of ways to achieve energy independence, and California Gov. Arnold Schwarzenegger has promoted the technology.

However, the idea does not make much sense: The only way to produce hydrogen that helps independence is by electrolysis of water. In the vehicle, hydrogen is converted into electricity with a fuel cell, which in turn powers an electric motor. The process is very energy inefficient: 25% of energy is lost in just condensing the hydrogen into a liquid so it can be transported. The function of the hydrogen is to transport electrical energy from a generating plant to an electric motor in the vehicle.

It is more energy efficient and much simpler, cheaper, and safer, because of hydrogen's flammability, to send the electricity directly from the generating plant to the batteries of an electric or hybrid vehicle. There are claims that current hybrid cars could go 60 miles on electricity alone, enough for most local travel, if modified so that the batteries can be recharged from an electrical outlet. If the hybrid was optimized to run on electricity, it could go farther before recharging. The gasoline engine would be needed only for long trips and would consume as little as 1 gal of fuel on a 500-mile trip.

Obviously, a large increase in electricity- generating capacity will be needed if all vehicles are to be electric, but that is possible with nuclear or nonpolluting coal plants.

Martin Vogel
Elkins Park, Pa.

• Email this article to a friend
• Print this article
• E-mail the editor