The future large-scale use of hydrogen as an energy carrier has been given considerable attention in congressional hearings, secretarial speeches, and by President Bush in his State of the Union address this year. A just-released report outlines the basic research required to turn the promise of a hydrogen economy into a reality.
The report summarizes the findings of DOE's "Basic Energy Sciences Workshop on Hydrogen Production, Storage, and Use" that was convened in May. This workshop was chaired by Dr. Mildred Dresselhaus of M.I.T., who has previously served as the director of the Department of Energy's Office of Science and who is now the chair of the Governing Board of the American Institute of Physics. The 175-page report was prepared by Argonne National Laboratory, and can be found at http://www.sc.doe.gov/bes/hydrogen.pdf
The workshop was charged by DOE Office of Science Associate Director Patricia Dehmer with identifying "fundamental research needs and opportunities in hydrogen production, storage, and use, with a focus on new, emerging and scientifically challenging areas that have the potential to have significant impact in science and technologies." Three panels reviewed basic research challenges involving hydrogen production, storage, and fuels cells and novel fuel cell materials.
The workshop's findings are presented in this report that is both readable by the general public and, particularly in a 65-page section on research directions, sufficiently detailed to outline basic research needs. These needs are considerable, and as the report states, "while the hydrogen economy represents a visionary strategy for our future energy security, significant scientific and technical challenges must be overcome to achieve its implementation." Revolutionary, rather than evolutionary, advances will be required for a hydrogen economy to be successful, the report explains.
The report's sections on the findings of the three panels describe the challenges. For instance, providing sufficient and cost- effective means to produce usable hydrogen will require an "intensive effort in both basic research and engineering." If fossil fuels such as coal are used, a carbon-neutral system would require the development of an economic and safe method for CO2 sequestration. Other production systems are described, including various forms of solar hydrogen, biological and biomimetic systems, and thermal energy. Efficient and effective hydrogen storage, particularly for vehicles, is critical. The transportation sector is the "most intensive driver for the hydrogen economy," the report states, but onboard storage for transportation uses is "one of the major challenges in achieving the hydrogen economy." Potential gaseous, liquid, and solid-state storage methods are described. Particular attention is given to metal hydrides, which researchers believe "may represent ideal storage systems." There are more than numerous metal hydrides, none of which thus far have met all requirements. Solving this problem will require a multidisciplinary approach involving, among other fields, physics and materials science. Nanoscience could, the panel found, "provide revolutionary new capabilities that will have a profound impact on hydrogen storage." The third panel reported on challenges involving fuel cells and novel fuel cell materials. The panel found that there will be a "long pathway" to the use of fuel cells in automotive applications, with a cost reduction of almost two orders of magnitude needed from what is expected to be the cost of mass-produced fuel cells using current technologies. Durability is another important issue to be dealt with. "The development of efficient and cost-effective fuel cell technology solutions for automotive and stationary applications presents a grand challenge that will take a substantial and sustained effort in chemical and materials research," the panel concluded.
In reviewing basic research needs involving production, storage, and use of hydrogen as an energy carrier, the workshop identified six "cross-cutting issues" common to each in areas such as catalysis, nanomaterials, and simulation. These issues are interdependent in many instances.
Two paragraphs in the opening pages of this report summarize the workshop's perception of the research challenges confronting a future hydrogen economy, and the best way to meet those challenges. They are as follows:
"The panels assembled to carry out this study started their investigation by focusing on the large gap between present knowledge and technology and that required by a hydrogen economy. However, as the panels carried out their work, optimism increased, as participants noted the many recent advances in chemistry, materials research, and computation that are opening up exciting new research opportunities. These opportunities have the potential to significantly narrow the knowledge/technology gap."
"Implementing the hydrogen economy represents perhaps one of the most fundamental and wide ranging influences on the social fabric of our times. It will lead to a reorganization of our energy culture that compares to the deployment of the fossil fuel economy in the late 19th and early 20th centuries, and the development of the electric power generation and distribution system in the mid and late 20th century. The benefits of the hydrogen economy to society are many and compelling. To realize these benefits, a strong program of innovative basic research aimed at making revolutionary advances in lowering the cost and raising the performance and reliability of the hydrogen economy is essential."