KENSINGTON — Kensington. -- In 1899, Henry Ford went to Thomas Edison and asked him to find a better way to power electric cars than with lead-acid batteries. After a century, the work continues and the results do not change: Twenty-one hundred pounds of lead-acid batteries can still only hold the energy equivalent of a single gallon of gasoline.
Of that 2,200 pounds, 1,400 are pure lead and more than 500 pounds are sulfuric acid. In 1998, electric cars will be pushed onto the road by legislative mandate, and that which has been precluded by laws of the physical world will be forced into existence by the laws of the social world.
Steam might seem an unlikely alternative to electricity as a way to power zero-emission cars. Yet steam engines that burn pure hydrogen and oxygen produce only pure water, which can be captured in a small reservoir and held for later use.
Steam power might seem outdated, though in fact more than a third of the energy used in this country produces steam for the production of electricity and heat. Steam technology is mature.
A friend and I have been trying to develop a light-weight zero-emission steam engine. Our goal is a 50-horsepower ''rocket-turbine'' that weighs less than five pounds. The idea is to make the engine so light that it becomes little more than a pimple on the butt of the fuel-storage system. A car powered by our engine would be light, powerful and economical, and it would have no exhaust.
Working on a steam engine leads to tangential thoughts about the properties of steam. The most powerful volcanoes, for instance, are steam-powered. When Krakatau in Indonesia exploded in 1883, the atmospheric shock wave was audible in Australia and measurable on the far side of the planet. Krakatau hurled several cubic miles of dust into the atmosphere which produced colorful sunrises and sunsets for years afterward.
Mount St. Helens was also a steam-powered explosion, and so was Pinatubo in the Philippines several years ago. The most colorful sunsets of the past few years I call Pinatubo sunsets.
About five years after Mount St. Helens blew, I was driving through western Montana, Idaho and eastern Washington. Fine dust from Mount St. Helens lay on the shoulders of the road nearly everywhere. I collected some in a film canister and brought it home. For a long time I wondered how a volcano could produce so much fine powder.
Recently, while I was working on the steam-engine project, I came up with a theory about the fine dust. I think this theory is a good one, taking into account, as it does, basic physical principles of steam as well as the geologic theory of plate tectonics (by which large chunks of the earth's crust rub against each another and sometimes one piece rides up and over another).
In the Pacific northwest, according to geologists, a piece of the floor of the Pacific Ocean is slowly being pushed down under the North American crustal plate. That water-soaked material is being pushed deep into the hot, viscous mantle of the earth.
As I see it, the wet oceanic floor material gets heated while being pressurized under tens, maybe hundreds, of miles of rock. The entrained water gets so hot and is under such huge pressure that it can be considered as either a liquid or a gas. Either way, it TTC contains a lot of energy. It also has an interesting property: The combination of pressurized water and near molten ancient sea floor is less dense, lighter, than the overlying rock.
Over centuries or millennia, though perhaps in periods as brief as only a few decades, mile-wide bubbles of what is essentially red-hot mud form and then rise through the heavy overlying rocks. A similar process in Louisiana produces salt domes: great blobs of salt from ancient dried-up seas take shape, then rise through rock in a kind of semi-solid flow.
When the hot mud gets closer to the surface where the overlying rocks are cooler and harder, it begins to flow in sudden jumps, breaking through layers of rock to move a few yards closer to the surface. When a cubic mile of red-hot mud moves several feet and then suddenly stops, the fluctuations of momentum can shake thousands of cubic miles of rock. The result is earthquakes, as the mud advances, then stops, then advances again.
When the bubble of hot mud gets close enough to the surface, the compressed steam can blow the top off a mountain -- or maybe blow the whole mountain away. The fine mineral dust is produced when pressurized steam is suddenly no longer pressurized. It's like taking the top off a bottle of soda water; but instead of carbonated water, the volcano spews steam-pressurized molten rock. At Mount St. Helens, when the hot mud broke through the side of the mountain, the steam became ordinary humidity, while the mineral parts of the red-hot mud -- saturated with super-high-pressure steam -- sprayed out as a fine, dry dust.
Volcanoes like the ones in Hawaii and Greenland don't involve steam; molten rock simply rises to the surface and flows out over it. But when ancient sea floor is involved in the thing, as in the Cascade Mountains and in Indonesia, the explosive power of a cubic mile or more of steam-powered mud affect the whole planet, physically and economically.
Steam is powerful stuff. It's hard to imagine a battery-powered volcano. Steam cars are a reasonable alterative to lead/electric ones. And, of course, gasoline still has a future.
Robert Burruss is an engineer who writes about technology and society.