We have reached an odd, maybe unique point in the history of technology, when the distant future is easier to imagine than the more proximate months and years ahead. Fifty years from now, most parties would agree, hydrogen fuel cell technology will power our world-everything from artificial organs to cruise ships and certainly our automobiles. By then we will have figured out how to produce cheap, CO2-neutral hydrogen-perhaps by using renewable energy sources such as wind and solar power to electrolyze water, perhaps with synthetic fuels (bio-ethanol and bio-diesel), perhaps by sequestering carbon from fossil feed stocks such as coal, perhaps with some fairy dust as yet undiscovered. By then the fuel cell industry will be sufficiently advanced to build very compact hydrogen tanks with enormous energy density, and fuel cells that are cheap enough for economy cars and robust enough for chilly northern climates-assuming global warming hasn´t already taken care of that problem for us.
The possibilities are tantalizing. Consider that, if America´s current rolling stock of some 230 million vehicles were powered by fuel cells, the fleet would represent around 17 terawatts of electrical production capacity (assuming an average fuel cell capacity of 75 kilowatts, about the current peak of the unit in the Honda FCX). That exceeds by a factor of 21 the nation´s current total electrical production of about 800 gigawatts. Fuel cell vehicles could be the rolling infrastructure of a new energy paradigm, the ultimate in distributed power generation. When parked, cars with fuel cells could act as pocket power plants, supplying power to the homes and offices to which they are docked, or feeding electricity into local grids during hours of peak demand.
You want some real future-car porn? Fifty years hence, the automobile will be a kind of transportation prosthesis, a semi-organic interface of man and machine that will, with its great reserves of energy and intelligence, be at the center of human existence. Today´s clumsy interface of steering wheel and pedals will be replaced with neuronal seats that will read your mind and navigate accordingly. Road-keeping and collision-avoidance technologies-the synthesis of GPS, traffic tracking, automatic cruise control and braking, and other here-and-now tech-will eliminate the need for "crash-worthiness" as our primitive minds now conceive of it, as rigid but bendable steel construction. The automotive chassis will be built from nanocomposites whose molecules will be arranged for maximum strength and lightness. The skins of future cars will be stretched over the vehicle like a silk stocking, adjusting dynamically according to load-expanding to accommodate four passengers, contracting to envelop the single driver like the suit of a downhill skier.
The automobile will at last fulfill the promise resonant in the words "autonomous mobility." Mass transit as we think of it now will seem as wrongheaded as eugenics. Automobiles' quantum-computer cores will be the archives of our memory, our machine adjuncts, our confidantes, in ways so profound and personal as to mock today´s limited PDA phones. We will have merged with our cars.
And they/we will be fast. As speeds increase, aero-tunneling "pores" will open up under the vehicle to increase downforce. The tail of the vehicle will draw back in the windstream, decreasing resistance and enhancing stability. There will be no rigid glass windows. The exterior world will be re-created inside the cockpit with panoptic verisimilitude like that described by David Gelernter in his book Mirror Worlds, offering infrared imagery, magnification, map overlay and other kinds of machine vision-for instance, virtual billboards or menus of restaurants along the route.
Speeds inside the tunnels will exceed those of today´s bullet trains. At the entrance, cars will surrender control to automated highway systems that will manage vehicle speeds, merging and spacing for optimal flow. Intercity tunnel conduits-and perhaps intercontinental megatunnels-could be depressurized to reduce aerodynamic drag, allowing speeds that ol´ Chuck Yeager could only dream about.
Well, that was fun. But as I say, that sort of far-horizon prognostication is fish-in-a-barrel stuff. Between here and the utopian ever after lurk dozens of interlocking issues of cost, technology and environmental impact for which there are no easy answers and a lot of complicated arithmetic.
Here's a for-instance: It appears that in the short term, the hydrogen economy is seriously overdrawn at the bank. We do not now have-or even foresee-an affordable, climate-neutral means of producing hydrogen in sufficient quantities and distribution to achieve energy nirvana in the transportation sector. If you burn coal to generate the electricity needed to obtain hydrogen from water, you´re polluting in order to create a nonpolluting energy source. Indeed, if the goal is greenhouse-gas mitigation, it makes the most sense to begin by tightening emission controls on electrical generation, which accounts for about 40 percent of CO2 emissions in the U.S., compared with 20 percent from cars and light trucks.
Bottom line: Fuel cell technology is gimpy and expensive and is likely to stay that way for years to come. There is a wonderful, probabilistic slap-fight going on right now in journals among engineers, energy experts and policy wonks about just how far or near that time horizon might be.