Building the Hydrogen Highway
Imagine pulling up to a service station, filling your tank with the most abundant element in the universe and driving away in just minutes with only water vapor emitting from your vehicle's tailpipe.
A too-good-to-be-true tailpipe dream? Not at all.
Hydrogen fuel cell vehicles are already in use. For example, in California, 200 fuel cell passenger vehicles and 16 buses are on the road. In London, as many as 50 hydrogen-powered taxis, 150 buses and six filling stations may be in operation by the 2012 Olympic Games.1 Germany and Japan have plans to build 1,000 hydrogen fueling stations.2
As safety, cost, regulatory, infrastructure and institutional barriers crumble, hydrogen fuel proponents are increasingly convinced that FCVs will ultimately reduce dependence on foreign energy sources and eliminate greenhouse gases that contribute to air pollution and climate change. In fact, ASTM International Subcommittee D03.14 on Hydrogen and Fuel Cells, part of ASTM International Committee D03 on Gaseous Fuels, has taken a key first step toward the commercialization of hydrogen as a vehicle fuel by publishing nine standards for sampling and testing. More standards are under development.
"The technology is here, now," says Jacquelyn Birdsall, project engineer with the California Fuel Cell Partnership in West Sacramento, Calif., and chairman of ASTM Subcommittee D03.14. Larry Watkins, program supervisor for the Technology Advancement Office at the South Coast Air Quality Management District in Diamond Bar, Calif., is equally enthusiastic. He has been driving a 65-miles-per-kilogram Honda FCX Clarity hydrogen FCV. "It's coming," he says of widespread hydrogen FCV transportation.
In the simplest terms, a fuel cell is an electrochemical device that combines hydrogen gas with oxygen to produce electricity. A fuel cell is quiet, and reportedly two to three times more efficient than combustion.3 It's also clean. According to Tracey Jacksier, R&\;D director of analysis and specialty gas programs at the Air Liquide Delaware Research and Technology Center, Newark, Del., "For the same driving distance and even with hydrogen produced from natural gas, FCVs today have the potential to reduce carbon dioxide emissions by about 40 percent compared to vehicles with internal combustion engines burning gas."
FCVs are hybrid vehicles\; they all have small batteries to augment the power from the fuel cell. But unlike battery vehicles that have short mileage ranges and long recharge times, FCVs can range from 210 miles (340 km) (Chevy Fuel Cell EV) to 430 miles (700 km) (Toyota FCHV-ADV) on four to six kilograms of pressurized hydrogen gas. Filling a tank takes only a few minutes.4
Plus, the technology is readily adaptable to other vehicles - from forklifts to trucks, to buses - and it's comparatively robust. According to Watkins, fuel cell stacks can now last up to 10,000 hours, "which is better than most conventional cars today." Researchers are even finding ways to reduce the cost of fuel cell stacks as much as 90 percent by replacing the pricey platinum used in the fuel cell with other metals.5 A recent CaFCP newsletter calls hydrogen FCVs "no-compromises" electric vehicles that can "meet consumer expectations for performance, range, durability and comfort."6
In addition to General Motors and Toyota, Honda, Hyundai, Kia, Mercedes-Benz, Nissan and Volkswagen have fuel cell vehicles on the road today. Honda and Mercedes currently lease vehicles directly to customers in the Los Angeles, Calif., area, and most FCV manufacturers expect to offer vehicles to consumers by 2015. The price for a Mercedes-Benz F-Cell is expected to be around $50,000.7
Beyond building vehicles, however, getting more wheels on the so-called "hydrogen highway" involves creating a fuel infrastructure supported by standards and regulations that ensure safety and quality.
Most hydrogen in the United States is produced by reforming natural gas - using super-heated steam to separate hydrogen from natural gas and water molecules. Some hydrogen used in motor vehicles is produced by alternative methods, such as reforming biomass or using renewable electrolysis of water. For example, solar photovoltaic panels at the SCAQMD refueling station currently help generate the 60 kilowatts of electricity needed to produce 24 kilos of hydrogen per day on-site. At California's Orange County Sanitation District, wastewater is transformed into electricity, hot water and enough hydrogen to fuel 50 FCVs a day.
In 2003, SAE International (formerly the Society of Automotive Engineers) compiled a list of non-hydrogen constituents in reformed hydrogen that could compromise the performance and durability of fuel cell stacks.
"In order for our standard SAE J2719 to be an actionable document, we had to include ASTM sampling and testing methods for each contaminant," notes Mike Steele, who is retired from General Motors and now serves as the California-based chairman of the SAE Fuel Cell Standards Committee.8
But SAE specifications presented a significant challenge. Birdsall explains, "SAE called for parts per billion of sulfur, such low levels that they required new methods of testing. Most labs had not previously been able to detect constituents at that low a level."
By 2008, California amplified the demand for standards by requiring that hydrogen fuel sold for motor vehicles meet the SAE specifications.
Working with manufacturers, regulators, government and industry representatives and academics, ASTM Subcommittee D03.14 developed sampling and testing methods for each constituent in hydrogen that can poison a fuel cell stack or reduce its performance. Birdsall points to just one of the nine currently published standards - D7652, Test Method for Determination of Trace Hydrogen Sulfide, Carbonyl Sulfide, Methyl Mercaptan, Carbon Disulfide and Total Sulfur in Hydrogen Fuel by Gas Chromatography and Sulfur Chemiluminescence Detection - as an example of what the committee has accomplished to date. Other standards address other constituents via different test methods. With the eventual publication of the additional proposed standards (one of which is currently in ballot), non-hydrogen constituents in reformed hydrogen that affect fuel cells will have been addressed.
For John Mough, a chemist with the California Department of Food and Agriculture and a D03 member, the ASTM standards allow his agency to start enforcing regulations and "provide a level of transparency for consumers and ensure that everyone knows what needs to be done, regardless of the source of the hydrogen." He adds that metering methods to measure the exact amount of hydrogen dispensed also need to be developed.
So far, only one temporary permit has been issued to one station in California to sell hydrogen as a motor fuel to the public, hinting at the challenge of building a hydrogen infrastructure. It's a chicken and egg situation with distributors needing a market and manufacturers needing distributors. The National Research Council estimates it will take $8 billion to support 10 million hydrogen FCVs through 2025. In comparison, it now costs $160 billion annually to maintain the existing gasoline infrastructure.9
The standards developed by D03.14 still need to undergo interlaboratory testing to ensure that different labs achieve comparable, reproducible results. Birdsall also anticipates new online testing methods to test hydrogen at hydrogen fueling stations instead of in laboratories.
Meanwhile, Steele reels off a number of SAE standards at the top of his stack. Two deal with hydrogen fuel nozzles and refueling protocols, serious concerns when dispensing highly compressed hydrogen gas. The nozzles, resembling gasoline pump nozzles, are expected to incorporate pressure lock devices, as well as engine recognition systems, so a 5000-psi (35 MPa) vehicle doesn't accidentally receive a fill-up for a 10,000-psi (70 MPa) vehicle. Two other standards, currently being reviewed by the National Highway and Transportation Safety Administration, involve fuel cell and electrical safety. "ASTM methods will no doubt be referenced in all our documents and play a critical role in their acceptance," says Steele.
Internationally, under the United Nations World Forum for Harmonization of Vehicle Regulations (WP.29), 30 nations, including the United States, Germany, China, India and Japan, are developing global technical regulations for hydrogen FCVs. In the United States, the regulations will be incorporated and promulgated as federal regulations by the U.S. Department of Transportation under the Federal Motor Vehicle Safety Standards. Other countries in WP.29 will also incorporate the GTR in their national regulations. Under the GTR process, explains Jim Ohi, a Denver, Colo.-based consultant with the U.S. Department of Energy, "hydrogen FCVs manufactured in different countries by different manufacturers will be able to be sold throughout the world."
But even with technology and standards falling into place, Ohi points out that switching from petroleum to hydrogen as a vehicle fuel won't happen overnight. Hybrid vehicles, first introduced in 2000, still account for about 3 percent of registered vehicles in the United States. "It takes about 30 years for the whole fleet to change," he says.
So, just as horses and buggies initially existed in concert with the first automobiles, expect to see gas, diesel, hybrid, electric, biofuel and compressed natural gas vehicles sharing roadways with hydrogen FCVs over the next few decades - or perhaps until petroleum shortages, environmental concerns and an expanding hydrogen fueling infrastructure direct our dollars and our vehicles onto the hydrogen highway.
1. Alok, Jha, "Hydrogen Taxi Cabs to Serve London by 2012 Olympics," The Guardian, February 22, 2010.
2. Ohnsman, Alan, "GM to Maintain Hydrogen Push as Plug-In Volt Readied for Sale," Businessweek, March 17, 2010.
3. California Fuel Cell Partnership, "Well to Wheels: A Guide to Understanding Energy Efficiency and Greenhouse Gas Emissions," www.cafcp.org/welltowheels.
5. Squatriglia, Chuck, "Discovery Could Make Fuel Cells Much Cheaper," April 22, 2011.
6. California Fuel Cell Partnership, "Well to Wheels: A Guide to Understanding Energy Efficiency and Greenhouse Gas Emissions."
7. Squatriglia, Chuck, "Discovery Could Make Fuel Cells Much Cheaper," April 22, 2011.
8. SAE J2719, Hydrogen Quality Guideline for Fuel Cell Vehicles.
9. Fuel Cell Partnership, "Hydrogen and Fuel Cells: It Won't Take Miracles."Adele Bassett is a freelance writer who has covered everything from youth gangs in Colorado to earthquakes in Connecticut while working for a variety of corporations and publications. She holds a B.A. in English, an M.S. in journalism and an M.B.A.