ENVIRONMENT | Protecting our natural resources
20 April 2005
U.S. Research Targets Hydrogen Fuel Cells, Infrastructure
Decision on commercial hydrogen economy likely 10 years away
Energy issues are critical to earth's environment. This article is part of series of articles on renewable energy, an increasingly promising element in future energy calculations.
Washington -- The 35th anniversary of Earth Day, April 22, 2005, represented a growing global commitment to a cleaner environment and to replacing finite stores of coal, oil and natural gas with renewable energy sources. One of the most challenging and potentially promising of these renewable resources is hydrogen.
Hydrogen is the simplest, most abundant element in the universe. The idea of using it as an energy source has been around at least since 1870, when Jules Verne incorporated the concept in his science-fiction classic, 20,000 Leagues Under the Sea.
Hydrogen does not occur naturally as a gas on Earth – it is always combined with other elements. Water, for example, combines hydrogen and oxygen (H2O). Many organic compounds also contain hydrogen, including the hydrocarbons that make up fuels such as gasoline, natural gas, methanol and propane.
As a source of power, hydrogen is highly efficient and produces almost no pollution.
In 2003, President Bush announced a $1.2 billion hydrogen-fuel initiative to reverse growing U.S. dependence on foreign oil by developing the technology for commercially viable hydrogen-powered fuel cells to power cars, trucks, homes and businesses.
The initiative included $720 million in new funding over five years to develop the technologies and infrastructure to produce, store and distribute hydrogen for use in fuel cell vehicles and electricity generation.
At the U.S. Department of Energy (DOE) National Renewable Energy Laboratory (NREL), Sue Hock, director of the Center for Electric and Hydrogen Technologies and Systems, says the work to develop hydrogen as an energy source also calls for public outreach and education, and the development of codes and standards for all aspects of hydrogen production and distribution.
“Here at NREL,” she said, “our main interest is in the production of hydrogen from renewable sources. We’re focusing on electrolysis, which uses electricity to split water into hydrogen and oxygen,” using renewable sources for the electricity.
Hydrogen also can be split photoelectrochemically – using a semiconductor (like silicon) immersed in an electrically conductive liquid called an electrolyte to split the water directly. Another possible renewable hydrogen source is algae or bacteria that produce hydrogen naturally. These are being genetically modified to produce greater amounts of hydrogen.
Hydrogen fuel cells -- proton exchange membrane (PEM) fuel cells -- are another important research area.
Fuel cells are “the reverse of electrolysis,” Hock said. “You put hydrogen and oxygen into the fuel cell and they’re combined. During the combination, electricity is one of the products.”
In a car, she explained, “you would have a hydrogen storage tank, combine it with air for oxygen, it produces electricity and basically from there it’s like an electric car. And the [remaining] output is steam – water vapor.”
DOE has identified hydrogen storage as the biggest technical challenge in effectively using hydrogen as an alternative fuel source, Hock said.
In testimony before the Senate energy and water appropriations subcommittee in 2004, David Garman, DOE assistant secretary for energy efficiency and renewable energy, said, “One of the major obstacles we face is developing the means to store sufficient amounts of hydrogen aboard the vehicle to provide a driving range of greater than 300 miles.”
“Hydrogen is not dense,” Hock said. “it’s a gas -- so to store enough of it you have to compress it at very high pressures, or you need to be able to store it chemically or somehow bond it with another material so you can access it easily,” she added.
Compressed hydrogen is the current standard: demonstration vehicles all have compressed tanks. DOE has identified three centers of excellence to pursue other technologies; one of those centers is NREL, where scientists are researching carbon storage.
The focus is on carbon nanotubes -- extremely thin (a diameter 10,000 times smaller than a human hair), hollow cylinders of carbon atoms. Because of the molecular structure of the carbon in the nanotubes, hydrogen easily bonds to the carbon and subtle changes in temperature or pressure will cause the hydrogen to be released.
“We’re starting to see promising results,” Hock said, “but it’s fair to say [the technology] is still controversial.”
While promising, this and other research show that the world is a long way from a hydrogen economy, in which hydrogen would be produced using coal, natural gas, nuclear energy and renewable energy; would be stored and transported for use; and hydrogen fuel cells would be used to power vehicles and produce electricity.
According to the 2004 report from the National Academy of Engineering, The Hydrogen Economy: Opportunities, Costs, Barriers, and R&D Needs, “Many of the technologies for realizing such extensive use of hydrogen in the economy face significant barriers to development and successful commercialization.”
The challenges, according to the report, “range from fundamental research and development needs to overcoming infrastructure barriers and achieving social acceptance.”
Nevertheless, the report said, a transition to hydrogen as a major fuel in the next 50 years could fundamentally transform the U.S. energy system. Especially critical for the transportation sector is dramatic progress in the development of fuel cells, storage devices and distribution systems.
“When you consider the alternatives for mobile applications – transportation – there aren’t many options,” said Bruce Logan, a professor of environmental engineering and director of the Hydrogen Energy Center at Pennsylvania State University.
“While you can use wind and solar and combustion of biomass to make electricity, the way to power a vehicle is very difficult,” he said. “You can use natural gas [methane], but that is a fossil fuel. You can make methane biologically as a form of renewable energy, but that also has a problem of combustion byproducts.”
Hydrogen is seen as a solution to two problems, he said, providing a transportation fuel and solving problems of pollution, because, in a fuel cell, all you get from the hydrogen reaction is water.
To boost technology development for hydrogen in transportation, DOE announced a Controlled Fleet and Hydrogen Infrastructure Demonstration and Validation Project in 2003 and the first partnerships were announced this year. Among them:
• DaimlerChrysler further will develop fuel cell vehicles in the United States, investing more than $70 million. The five-year partnership links DaimlerChrysler, BP Amoco PLC and other companies as partners to increase public awareness about fuel cell vehicles and the hydrogen economy.
• General Motors (GM) Corporation signed a five-year, $88 million agreement to build a 40-vehicle fuel cell fleet and further develop the technology. GM will deploy fuel cell vehicle demonstration fleets in Washington, New York City, California and Michigan. In a separate agreement, Shell Hydrogen will set up five hydrogen refueling stations in Washington, metropolitan New York, the corridor between New York City and Washington and California.
• ChevronTexaco Technology Ventures (CTTV) unveiled a Chevron hydrogen energy station in February in California as part of a five-year DOE cost-sharing program to demonstrate safe, practical hydrogen technologies. CTTV is collaborating with Hyundai Motor Company and other partners.
Internationally, the United States works with the International Energy Agency’s hydrogen working group to exchange information and participate in joint research projects with many other countries.
The United States also participates in the International Partnership for the Hydrogen Economy (IPHE), established in 2003 to accelerate the transition to a hydrogen economy. Partners include 15 countries and the European Commission.
The IPHE will help organize and implement international research, development, demonstration and commercial-use activities that advance the transition to a global hydrogen economy.
An initial IPHE focus, Hock said, is on hydrogen codes and standards, which are critical to making sure hydrogen can be used safely. NREL has the lead coordinating role in developing codes and standards specific for hydrogen, including safety testing and analysis of bulk storage systems, fuel-dispensing equipment, onboard vehicle storage and piping for hydrogen distribution.
To develop such standards, NREL is working with standard-setting organizations and other countries, including some European nations, Japan and Canada.
“I see hydrogen as the ultimate solution for many of our energy and environmental problems,” Hock said, “but a lot of research needs to be done before we’re ready to make the transition to hydrogen.”
According to the DOE Hydrogen, Fuel Cells & Infrastructure Technologies Program Multi-Year Research, Development and Demonstration Plan, published in February, a coordinated effort will be made to develop a hydrogen fuel-cell vehicle and the supporting infrastructure of manufacturing plants, distribution and storage networks and fueling stations.
In 2015, the United States will make a decision about whether the technology – hydrogen production, delivery, storage, fuel cells – and related and codes and standards should be fully commercialized.
“There’s a lot of promise in these technologies and a lot of basic research is being conducted,” Hock said. “But we won’t really know if we can make the decision to move forward for 10 years.”
Information about DOE hydrogen and fuel cell initiatives is available at http://www.hydrogen.energy.gov/initiatives.html
Information about the International Partnership for the Hydrogen Economy is available at http://www.iphe.net/
For additional information on renewable energy resources, see Washington File articles on solar energy, biomass, wind power and green power marketing.
