Carbon Nanotubes Are One Possibility.

At NREL, researchers are looking into reversible chemical storage materials, including carbon-containing materials such as carbon nanotubes—tiny, lightweight carbon cylinders, each having a diameter equal to several hydrogen molecules. Heben, and other NREL scientists have shown that hydrogen may be drawn up into these carbon tubes just as water is drawn up into a drinking straw. So, they are working on fabricating bundles of aligned nanotubes. These would essentially be lightweight hydrogen "sponges," ideal for a vehicular hydrogen storage system.

In addition to hydrogen storage, NREL researchers and analysts are also focusing their efforts on hydrogen production and delivery, codes and standards, fuel cells, and vehicle and hydrogen infrastructure analysis. "Our hydrogen research really cuts across all of the Lab and everything we do," says Sue Hock, director of NREL's Center for Electric & Hydrogen Technologies and Systems. "There is no one clear path to the hydrogen vision. The answer will be in a diversity of solutions.