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No matter how efficiently man exploits, delivers and uses the earth's remaining oil and gas deposits, they may well be all gone in little more than a half-century. Coal deposits will last centuries, but getting at them without ruining the landscape and burning coal without hopelessly polluting the atmosphere will require new technologies and additional inputs of energy. Yet the Nixon Administration's new budget calls for only $770 million for research and development in the energy field —far less than the $2 billion a year some scientists say is necessary to develop in time the alternative energy sources necessary to maintain a technological civilization. Some of the more promising sources:
SYNTHETIC FUELS. The vast resources of coal could be used to produce a variety of synthetic fuels. In coal gasification, for instance, coal is brought in contact with steam. Hydrogen atoms in the vapor combine with the coal's carbon atoms to produce a hydrocarbon similar to natural gas.
A major hitch to coal-gasification schemes is cost; all the heating and processing must take place in expensive aboveground plants. But Physicist Glenn C. Werth and his colleagues at the AEC's Lawrence Livermore Laboratory in California have proposed a less expensive alternative. They believe that it may be possible to create methane in the earth by forcing oxygen and water into fractures created with the help of explosives in coal seams. The cost, they figure, would be between 400 and 600 per 1,000 cu. ft., less than the price of liquefied natural gas now delivered from overseas by tanker.
The vast amounts of shale found in Colorado, Utah and Wyoming could also be important sources of oil, yielding about 25 gallons for every ton excavated. Both shale mining, which leaves great quantities of waste material above the surface, and strip-mining for coal despoil the landscape. But the exploited landscape could satisfactorily be restored—at a price.
There has also been a renewal of interest in another artificially produced fuel: hydrogen, the lightest and most abundant element in the universe, which can readily be produced by electrolysis of water molecules. Highly combustible, it has already proved its importance as a space-age fuel: it was a reaction of liquid hydrogen (at a temperature of less than — 350° F.) and liquid oxygen that gave NASA's big Saturn 5 rockets their final boost to the moon. Properly handled, hydrogen might be burned to heat homes, generate electricity or power cars; the only major waste product is water. A more direct use of hydrogen could be in efficient fuel cells —battery-like devices, also used in spacecraft, that produce an electric current from a reaction of hydrogen and oxygen.
MAGNETOHYDRODYNAMICS. Even the best fossil-fuel plants operate at about 40% efficiency. Only that portion of the fuel's energy is converted into electricity; the rest is simply turned into waste heat. A more efficient power-generation scheme, magnetohydrodynamics, creates an electric current by passing a stream of hot, ionized gas at high speed through a powerful magnetic field. MHD plants should be able to operate at nearly 50% efficiency. Unfortunately, the U.S. is leaving almost all research and development in MHD to the Russians, who figure that it will eventually fill 10% of their electrical needs.