Science, the weekly publication of the American Association for the Advancement of Science (AAAS), is focusing on the hydrogen economy in its August 13 issue. You can see short abstracts of the articles as a guest; full access requires membership, subscription, or heading to the local library.

The result, at normal human-scale temperatures, is an invisible gas: light, jittery, and slippery; hard to store, transport, liquefy, and handle safely; and capable of releasing only as much energy as human beings first pump into it. All of which indicates that using hydrogen as a common currency for an energy economy will be far from simple. The papers and News stories in this special section explore some of its many facets.

Consider hydrogen’s green image. As a manufactured product, hydrogen is only as clean or dirty as the processes that produce it in the first place. Turner describes various options for large-scale hydrogen production in his Viewpoint. Furthermore, as News writer Service points out, production is just one of many technologies that must mature and mesh for hydrogen power to become a reality, a fact that leads many experts to urge policymakers to cast as wide a net as possible.

The Viewpoint by Demirdöven and Deutch and Cho’s News story describe different intermediate technologies that may shape the next generation of automobiles.

Two generations down the line, the world may end up with a hydrogen economy completely different from the one it expected to develop. Perhaps the intermediate steps on the road to hydrogen will turn out to be the destination. The title we chose for this issue—Toward a Hydrogen Economy—reflects that basic uncertainty and the complexity of what is sure to be a long, scientifically engaging journey.

Coontz and Hanson