- The Washington Times - Friday, April 25, 2003

During his State of the Union message in January President Bush asked Congress for $1.2 billion to spur the development of hydrogen-powered vehicles. Was this a pie-in-the-sky idea to create political favor or does the idea have merit? When everything is summed up, hydrogen-fueled vehicles are a little of the former and a lot of the latter. While hydrogen proved a very bad idea for early airships (witness the Hindenburg’s explosive departure from history), it makes a lot of sense for 21st-century vehicles.
  Hydrogen is the most common element in the universe. It constitutes billions upon billions of suns, including our own, and they, in turn (through very complicated and not entirely worked-out laws of extreme high-temperature physics), create all the other elements that combine in endless ways to make up the planets, asteroids and comets. Our planet is 75 percent water, which is made up of hydrogen and oxygen, but in nature hydrogen as a free atom is virtually nonexistent. It also makes up a huge amount of the world’s oil, hence oil’s classification as hydrocarbons.
  Hydrogen is quite flammable, making it a great source of heat energy. It has about one-fourth as much energy by volume as gasoline, but about three times as much by weight. When it burns, the only byproduct is water. Those properties make hydrogen a very attractive energy source for powering automobiles and other things. The only problem with using hydrogen is its production it has to be chemically separated from water or hydrocarbon compounds.
  There is no point in producing hydrogen if its production uses more energy than it contains, or if its production releases greenhouse gases or other pollutants. Obtaining hydrogen from crude oil, natural gas or any other fossil-based material is, therefore, out of the question for the foreseeable future.
  On the other hand, obtaining hydrogen from biomass is considered feasible because that source is considered by environmental specialists as “CO2 neutral.” That is, the biomass materials have drawn as much carbon dioxide from the air while they were alive as they discharge during later use as a hydrogen source.
  The best way to get hydrogen is through electrolysis: passing direct current through two electrodes in water, releasing gaseous hydrogen and oxygen (everyone did this in high school chemistry class). This process is clean, but the electricity itself has to be produced in some way that is environmentally advantageous. In other words, if the electricity is created through the burning of fossil fuels, there is no net benefit.
  Electricity can be produced through three environmentally friendly methods: hydroelectric power; solar collectors and wind generators.
  Rivers, streams and man-made lakes next to dams are creating all the hydroelectric power they can now and environmental concerns are likely to prevent the construction of many more facilities. That method of hydrogen production, therefore, is mostly discounted.
  Solar collectors can generate electricity in two ways:
  Photovoltaic cells (devices that collect solar energy and convert it to electricity) can be used to generate the power to separate hydrogen from water. Limitations on this method include the availability of sunlight (only feasible in subequatorial regions) and the cost and efficiency of photovoltaic cells. Because the sun puts out only approximately 4 watts per square foot of available energy, very large arrays of cells must be used.
  Solar heat collectors are another way to generate electricity. Instead of costly photovoltaic cells, parabolic mirrors collect the sun’s energy and focus it into pipes containing some sort of coolant (usually a heat-resistant oil). Temperatures in excess of 400 degrees Celsius (752 degrees Farenheit) can be generated that, in turn, produce steam. This steam powers turbine generators that produce electricity.
  Wind-powered generators are also feasible. A wind generator consists of a set of blades (a propeller), a nacelle that contains a generator and a tower on which the apparatus sits. Control electronics and switching systems complete the generator. They operate on the same principle as steam- or water-powered turbines, but because air is far less dense than water or steam, much larger blades must be used to extract the same amount of energy from the wind.
  Wind generator blades are typically about 30 feet in diameter and must sit on towers located in areas where the wind is relatively constant year-round. Because the energy in the wind is a function of the cube of its speed, constant winds of 10-to-15 mph are normally required to make wind generation economically effective.
   The same limitations as solar also apply to wind: the relatively small geographic areas of the Earth that are suitable for such installations; and the overall space required. Solar and wind “farms” occupy vast acreage on which to operate, limiting their use to government-owned land or that which is unusable for any other purpose.
  Back to hydrogen
  Assuming hydrogen can be produced economically, there is still a major obstacle: infrastructure. Some means must be created to supply hydrogen to vehicles in sufficient quantities and over a huge geographical area, to duplicate the availability of gasoline.
  That’s no small task, of course, because the gasoline infrastructure has evolved over 100 years to be a model of convenience and safety. Any large-scale development of a hydrogen infrastructure will have to be a collaboration between government and industry, including manufacturers and aftermarket suppliers. Industry officials say they are ready to join the government in what will be one of the largest overall development projects in recent history.
  From a practical standpoint, hydrogen can be stored as either a gas or a liquid. The most energy-efficient way to do so is as a liquid, although in this form its temperature remains at minus 253 degrees Celsius.
   The chemical industry already transports hydrogen in this way, and the engineering difficulties long have been solved.
  Scaling up hydrogen production and distribution will not be easy or inexpensive. Currently only about 54 million metric tons (a metric ton is 2,204 pounds, or 1.1 tons) of hydrogen are produced worldwide each year.
  A shift to hydrogen power for the world’s vehicles, not to mention home-heating uses, would require many, many times that production and the distribution system to handle it, all of which must be cost-effective, convenient and safe.



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