A transition to hydrogen as a major fuel in the next 50 years could significantly change the US energy economy but technical, economic, and infrastructure barriers need to be overcome, says a new report from the National Academies’ National Academy of Engineering and National Research Council.
In the best case scenario, the transition to a hydrogen economy would take many decades, and any reductions in oil imports and carbon dioxide emissions are likely to be minor during the next 25 years, said the committee that wrote the report.
‘Our study suggests that while hydrogen is a potential long-term energy approach for the nation, the government should keep a balanced portfolio of research and development efforts to enhance US energy efficiency and develop alternative energy sources,’ said committee chair Michael Ramage, retired executive vice president at ExxonMobil Research and Engineering, Moorestown, NJ.
In last year’s State of the Union address, President Bush announced a $1.2 billion hydrogen fuel initiative which, combined with the existing FreedomCAR (Cooperative Automotive Research) initiative at the US Department of Energy, aims to make it practical and cost-effective to use clean, hydrogen-powered vehicles by 2020. But the new initiative has technological and economic challenges to overcome, and concerns about cost, environmental impact, and safety need to be addressed, the committee said.
Hydrogen can be produced using fossil fuels such as natural gas and coal; renewable energy sources such as wind, organic matter, and sun or nuclear energy. Currently, hydrogen is produced in large quantities at reasonable cost for industrial purposes by breaking down natural gas into hydrogen and carbon dioxide. But to achieve widespread use of hydrogen, especially as a fuel for automobiles, it must be produced cost-effectively either in large plants or in smaller facilities at or near vehicle fuelling stations. If the hydrogen is produced in large plants, infrastructure must be put in place to distribute it to fuelling stations. And hydrogen storage technologies must be developed for vehicles that will give consumers the range between refuellings that they expect, the committee said.
The report points out that 10 percent of the natural gas used in the US today is imported and that significantly more will be in the future. Thus, while the most cost-effective source of hydrogen for the long run is probably natural gas, its long-term use as a source of hydrogen would not increase U.S. energy independence, the report says.
Fuel cells, which are devices that combine hydrogen and oxygen to produce electricity, are one of the most promising power sources for clean, hydrogen-fuelled transportation, but their cost must be significantly reduced and their reliability should be increased, the report says.
Because hydrogen is flammable and explosive, safer systems for transporting, storing, and handling it also must be developed, the report says. Although hydrogen is professionally managed and used safely in industrial settings, the widespread use of hydrogen in a consumer setting will require the creation of new systems to ensure safety.
Most current ways of producing hydrogen are expensive, but if many technical problems are solved and technologies reach a mature stage of development, hydrogen could be produced and used in fuel cell vehicles at reasonable cost, the committee said. The most significant challenge will be the high cost and logistical complexity of hydrogen distribution to fuelling stations, the committee added.
‘We are facing a ‘chicken and egg’ problem that will be difficult to overcome,’ Ramage said. ‘Who will invest in the manufacture of fuel cell vehicles if there is no widespread hydrogen supply? At the same time, who will invest in facilities to produce hydrogen if there are not enough fuel cell vehicles to create sufficient income for the hydrogen producers?’
An initial stage where hydrogen is produced on a small scale using natural gas or electricity seems likely, the report adds. For this to happen, production costs for small units must be sharply reduced, which may be possible with expanded research. And during this transition, other technologies for producing hydrogen on a larger scale can be developed.
The committee reviewed DOE’s research, development, and demonstration plan for hydrogen, and was impressed by its thoroughness and the agency’s progress over time. However, DOE should better co-ordinate and integrate the efforts of all offices involved in its hydrogen program, the committee said.
‘DOE leadership is critical to setting up a hydrogen program for the future, but its current program has tried to establish activities in too many areas,’ Ramage said. ‘Prioritising efforts, establishing milestones, and adjusting the program based on results are extremely important. Also, the program’s odds of success in bringing the United States to a hydrogen economy will be greatly increased if DOE partners with a broader range of academic and industrial organisations.’
Also, to address the hurdles facing hydrogen production, distribution, and use, DOE should shift its resources and attention from some development activities to more exploratory work, the report says. For example, research should be increased in the areas of distributed hydrogen production systems, hydrogen storage, and solar energy for hydrogen production.
Currently, producing hydrogen from coal – a large domestic resource – results in emissions of carbon dioxide into the atmosphere. To reduce these emissions, large-scale production of hydrogen from coal would need to incorporate captured and stored carbon, the report says. The DOE program should accelerate development and early evaluation of carbon capture and storage technologies and further investigate production methods that do not result in emissions, such as wind, the sun, and nuclear heat processes, the committee added.
The study was sponsored by the US Department of Energy. The National Research Council is the principal operating arm of the National Academy of Sciences and the National Academy of Engineering.
Copies of The Hydrogen Economy: Opportunities, Costs, Barriers, and R&D Needs will be available this spring from the National Academies Press on the Internet <a href=’http://www.nap.edu’>here</a>.