Jules Verne once prophesized that ‘water is the coal of the future.’ On Wednesday, March 12, Theanne Schiros (ESRB) encouraged her colleagues at SSRL to help make that happen. About 30 people came to the hour-long talk on "Scientific Challenges and Research Opportunities in Hydrogen Energy Technologies," and many stayed afterward to discuss issues raised in the talk.

SSRL Deputy Director Jo Stöhr introduced Schiros, saying that "the broader topic—the future of energy resources in the world—is an important one."

"DOE has estimated that CO2 emissions will increase 60 percent in the next 50 years," Schiros said, "with potentially dramatic climate change consequences. This is why developing alternative fuel sources, like hydrogen, is so important." Schiros said she hoped her talk would inspire some SSRL researchers to work on effective means of making and storing hydrogen.

Photoelectrolysis is a one-step process in which sunlight is absorbed in a semiconductor, splitting water into hydrogen and oxygen. This is one of the ways hydrogen can be produced and used as an inexhaustible, clean energy carrier. Hydrogen has enormous potential to form the foundation for a globally sustainable, pollution free, renewable energy system and meet growing energy demands while reducing, and eventually eliminating, CO2 and other greenhouse gases. (graphic by DOE)

Hydrogen cells are already available for use in cars and in fact hydrogen fueling stations have appeared in Iceland and Southern California. However they are expensive and the current method of storing the fuel—cryogenics—is energetically inefficient. Moreover, fossil fuels are required to make the hydrogen.

There are many potential ways to make hydrogen renewably. Schiros’s own thesis work focuses using the sun’s energy to strip hydrogen from water, a process called photocatalytic decomposition. Other possibilities for hydrogen production include biomass decomposition and photobiological processes. For example, algae can be forced to make hydrogen, and decomposing peanut shells can produce hydrogen along with fertilizer while sequestering CO2 in the form of solid carbon.

A bigger problem is storage and transport of hydrogen, which is normally a gas. Some materials, including carbon nanotubes, have shown promise in absorbing and desorbing hydrogen as needed, and would take up little space. Before these can be regularly used, though, some way of making hydrogen cells from these materials cheaply and reliably must be developed.

"There are good reasons for making this effort," according to Schiros. Unlike many other energy sources, "with hydrogen cells the payoff is huge and they essentially have no negative consequences."

For more information on hydrogen energy technology, see: http://www.eere.energy.gov/hydrogenandfuelcells/