Water World: Powering the Nation with Hydrogen
Imagine a world powered almost entirely by an infinitely abundant and totally clean fuel. Hydrogen is just such a fuel: the most common element in the universe, it can be made from water and used to generate ordinary electricity for homes and cars. In such a world energy would come from an easily stored and domestically produced fuel. Electric power and transportation would be totally clean and entirely free of messy geopolitical problems. Peering into the glass, we could see people using "cHars" -- run on powerful but silent fuel cells -- as mobile power plants. Plugging the home into the family car in the evening would offset the peak loads created by heating, air conditioning, lighting, and recreation. At work, employees could receive a bonus check every month for contributing power to the office park "grid." Unlike fossil fuels used in today's cars and power plants, the only by-product of hydrogen power would be pure water.
With hydrogen the challenge isn't finding a supply, but extracting the hydrogen cheaply and cleanly.
The Fuel Cell Promise
Despite nearly two decades of investment in alternative energy sources, the world remains reliant on fossil fuels. The world's supply of these fuels, however, remains relatively scarce. And despite technological advances, fossil fuels are inherently polluting: they can only be scrubbed, cleaned, and catalytically converted to a degree. During the past two decades, however, dramatic advances in a fairly old technology, the fuel cell, have opened up the possibility that another fuel, hydrogen, could power the world. A fuel cell is an electrochemical device similar to a battery, but unlike batteries a fuel cell requires fuel and never needs recharging. The input is hydrogen fuel, and the output is heat, electricity, and water.
Fuel cells have been around for decades (they have been used in the space program since the 1960s), and the notion of a hydrogen economy -- in which hydrogen-powered fuel cells deliver energy for homes, businesses, and vehicles -- has been perennially popular. As with any alternative technology, however, key questions remain about the viability of fuel cells. One of the obstacles is cost. A second is making the hydrogen, for despite its abundance hydrogen must still be extracted from water or other substances, and this process, too, requires energy, technology, and money.
Because no infrastructure exists to produce and distribute large amounts of hydrogen, today's fuel cells are largely reliant on fossil fuels such as natural gas, the same substance that heats millions of buildings and homes across the country. Natural gas-powered cells use a reformer, a device which extracts hydrogen from the fossil fuel and feeds it into the cell, creating electricity and power. The leftover carbon is emitted into the atmosphere as carbon dioxide, a greenhouse gas. Yet fossil fuel-powered fuel cells are still much cleaner than fossil fuel combustion. If the dream of a hydrogen-based society is to be realized, such natural gas-powered cells will probably provide the transition.
Such a transition may already be in the works. Fuel cell makers are proceeding along two tracks: one developing fuel cells for use in automobiles, the other building larger cells for generating power for homes, businesses, and industries.
Hydrogen in the Tank
In the case of automobiles, most optimism centers around fuel cell hybrid vehicles employing standard fuels familiar today, with methanol and gasoline as the leading contenders. The major car manufacturers have been working to commercialize fuel cell technologies for automotive use; DaimlerChrysler, Ford, and General Motors, the three members of the Federal Partnership for a New Generation of Vehicles (PNGV), have made fuel cell hybrid vehicles powered by gasoline, methanol, or natural gas a research priority. Demonstration fuel cell buses using natural gas and methanol are now in operation in various cities around the country, and some hybrid vehicle concept cars have been demonstrated. In California, whose Air Resources Board has recently reiterated its 2003 zero-emissions vehicle (ZEVs) mandate, fuel cells are seen as a cornerstone of efforts to comply with national air quality standards. The state is focusing efforts on commercializing fuel cell vehicles fueled by methanol or gasoline. Such vehicles could be commercialized in the California ZEV market as early as 2004.
Three key obstacles for fuel cell vehicles are the cost of the fuel cells, the cost of making the hydrogen, and the problem of hydrogen storage. Making a fuel cell as powerful and cost-effective as the internal combustion engine -- a technology that has been mass-produced for nearly a century -- is no small feat. As for the hydrogen fuel, there are questions about whether it should be produced through on-board reforming, at fueling stations, or at large-scale, centralized facilities. On-board reforming of natural gas, methanol, or gasoline would enable the industry to use fuels already common today. But on-board reforming adds to the cost of each vehicle, and the reformers require energy as well. Alternatively, hydrogen could be generated at stations similar to today's gas stations, then stored on-board. Current methods of on-board storage pose problems, however. As a gas, hydrogen takes up too much space: 7 cubic feet for a car with a 350-mile range, according to one study. Storing hydrogen as a liquid is costly and requires energy. Finally, though hydrogen can be stored at high density in metal alloys called hydrides, those available at present would add too much to a vehicle's weight to be practical. New breakthroughs -- possibly in carbon nanostructures, which could also store hydrogen -- are needed before hydrogen can become the fuel of choice in transportation; in the meantime, car makers will most likely choose on-board reforming of conventional fuels.
Power to the People
Although fuel cells have received plenty of attention from car makers, the ability to generate both electricity and heat also makes them attractive anywhere energy is used. In 2000, the market has richly rewarded companies working on stationary fuel cells for businesses and homes, with several new fuel cell IPOs (initial public offerings of new company stock) riding high and more start ups in the works. Most plans call for stationary fuel cells using natural gas reforming. International Fuel Cell, a subsidiary of United Technologies, has commercialized a 200-kW natural gas fuel cell for office building use (enough energy to power 200 homes, or one large office building); these devices go for $1 million apiece, well above the cost of other generation technologies. Newer fuel cell technologies along with competition and mass production could bring the price down to a range comparable to other power technologies (though it's important to bear in mind that the competition is also a moving target). Plug Power -- a new start up -- and IFC are both working on small, 7 kW fuel cells for use in homes and small businesses -- again relying on natural gas as the fuel. Larger fuel cells for electric power generation are also under development by such firms as Fuel Cell Energy and Siemens-Westinghouse. Because of their small size, fuel cells are also useful in places where methane, a potent greenhouse gas, would otherwise be vented into the atmosphere, such as at landfills and gas drilling operations.
Although alternative energy research in the past has been driven by government investment, a great deal of excitement surrounding fuel cells has been generated by the electricity deregulation movement. Today, electric power is typically generated in centralized coal, nuclear, and hydroelectric power plants and then sent into urban areas over costly high-voltage transmission lines. Such lines are unsightly, costly, and inefficient -- roughly 8 percent of all U.S. electricity is lost over the transmission and distribution system. Because fuel cells are modular, quiet, and clean, they can be placed right in buildings, houses, and factories, thus increasing efficiency while reducing the need for new power lines. Furthermore, deregulation and a recent shortfall in power generation has meant a decline in the reliability of power and, in many areas, unheard of price spikes. Each of these factors has helped propel the movement toward distributed generation -- power that is generated near or at the place where it is consumed, as could be the case with fuel cells.
As with other alternative technologies, a major roadblock is costs, which generally can't come down without mass production. Advocates of fuel cells hope that the diverse array of possible fuel cell applications will speed their adoption. One hope is that, in a deregulated energy market, more businesses and energy companies will turn to distributed generation. The first markets for fuel cells will be in isolated locations, as well as in industries that need high-quality, uninterruptible power such as hospitals, data-storage facilities, and possibly e-commerce firms. Eventually, the hope is that quiet and clean fuel cells will be attractive for cogeneration, where the efficiency of combined heat and power generation could render them cost-effective even at a premium to other sources of power. So although a lot still depends on the ability to bring down costs, there is reason for optimism that a solid market for stationary fuel cells will emerge within the next few years. Moreover, the initial market doesn't need to be large to have an impact on the rate of technological change.
Once fuel cells are widely adopted, where and when does hydrogen come in? The challenge is to create an infrastructure for producing, transporting, and distributing the hydrogen in a way that is itself clean. Today the U.S. annually produces 8.5 billion kilograms of hydrogen for industry, usually through steam reforming of natural gas. After production, typically the hydrogen is transported in liquid form by chemical trucks. The high volume of hydrogen required by a hydrogen economy would require pipelines like those now used to pump natural gas around the country. Although they are expensive, two such pipelines already exist in Louisiana and Texas, supplying hydrogen for local industrial purposes.
Making, Storing, and Moving Hydrogen
Assuming fuel cells and hydrogen work out, how long will it take? Building a hydrogen infrastructure will be an expensive proposition. The Argonne National Laboratory has estimated that the cost for building production facilities and pipelines sufficient to meet U.S. energy needs could be as high as $300 billion, with distribution costing another $175 billion, coming to roughly $3.00 per gallon of gasoline equivalent. And that price doesn't account for operating the infrastructure, the cost of the feedstock itself (such as natural gas), or the cost of transporting and storing the hydrogen. The build-out of such a system would most likely take place very gradually, as the fuel cell market takes shape. In California, for example, the California Fuel Cell Partnership, a public-private entity implementing the state's alternative vehicle program, has broken ground on the nation's first hydrogen fueling station, which it expects will power a dozen or more demonstration vehicles beginning in 2001. As fuel cells go mainstream, such stations could proliferate.
Another major hurdle is finding a way to produce hydrogen that is itself clean. While hydrogen is inherently clean burning, steam reforming of natural gas releases more carbon dioxide into the atmosphere than combustion of the natural gas feedstock alone. Some analysts believe that carbon from fossil fuel sources of hydrogen could be sequestered. Since 1996 Norway's Statoil has reinjected carbon dioxide from natural gas extraction into reservoirs in rock thousands of feet beneath the ocean floor. This and other methods of carbon sequestration or storage carry substantial costs in terms of both money and energy. Other forms of sequestration, such as reinjection of carbon dioxide to aid in oil exploration, are more economical, but their environmental benefits are not yet fully understood.
Fossil fuels are not the only source of hydrogen, of course: hydrogen can be extracted from water as well. If the energy for this extraction process were itself derived from a renewable energy source, hydrogen and water would form a clean and renewable energy loop. Some possible ways of obtaining hydrogen from water are direct. For example, research is now being conducted on photobiological ways of producing hydrogen that rely on specially modified algae that can form hydrogen with very little carbon impact. It is also possible to produce hydrogen from water electrochemically using photovoltaic electrodes. Other renewable routes for producing hydrogen from water are indirect: they rely on electricity which would be generated from wind, solar, hydro, or biomass. Of course, renewable electricity sources themselves face many technological obstacles.
Whatever the route to hydrogen adoption, everything now hinges on the ability of fuel cell researchers and manufacturers to build a product that can capture a meaningful slice of the market -- the same problem alternative fuel advocates have been trying to crack since the energy crisis of the 1970s. This time around, the tea leaves appear to be pointing in the right direction, with dozens of companies pushing fuel cell technology for a diverse portfolio of mass-produced applications. The question seems to be not whether fuel cells will become viable, but how large a market share they will command, and whether hydrogen -- the ideal fuel from an environmental standpoint -- will eventually come to power them.