French energy experts have looked at it this way for some time: If 20 percent of the country's agriculture was used to feed the horse years ago, why not set aside 10 percent of the country's farmland to feed 25 percent of the motor vehicles today?
Now the government has responded. By 1990, according to an energy plan announced recently, 25 to 50 percent of France's requirements for vehicle fuel will be met by petrol substitutes, or "carburols," coming from vegetable matter grown on 3.8 to 4.9 million acres of the country's 74 million acres now under cultivation.
In five years -- if all goes well -- 1.5 million tons of French-produced carburol will be mixed every year with existing petrol supplies, currently running at 17 million tons a year. By 1990, carburols could account for 50 percent of fuel use if land reconversion and technology programs roll right along.
Meanwhile, as an important part of the government's massive renewable energy resources program, emphasis will be placed in the short term on methanol-based carburol fuels derived from coal, gas, and heavy oil wastes. Later, the emphasis will shift to using the so-called acetonobutylique process, a technology developed by the French National Industry Research Center that relies exclusively on vegetable raw materials.
For the time being, French scientists have ruled out producing ethanol-based carburols -- such as those distilled from sugar cane and maize in Brazil and the United States. Specialists say these would be two to three times as expensive as gasoline to produce in France, where the feedstocks (sugar cane waste and cheap coal) are not readily available. The scientists say that the French-made methanol-based carburols are already price competitive.
The current carburol program -- announced in January 1981 -- is part of a project to develop renewable energy resources whose broad outlines were revealed last April. It called for increasing government investment in "soft" energy development from 140 million French francs ($28 million) in 1980 to 210 million francs (about $42 million) this year, with roughly three-quarters of the money used on "biomass" research. It predicted that renewable sources would be supplying 5 percent of the country's energy needs by 1990, or 10 to 12 million tons of oil equivalent (TOE). They now supply 1.5 percent. "Biomass" sources alone would be supplying 7.5 to 9 million TOE by the end of the decade, the government says.
Energy experts at European Community headquarters in Brussels have estimated that biomass sources could meet 5 percent of the 10-nation Community's short-term energy requirements. They have been especially encouraging to France ,which has nearly twice as much arable land as any othe r EC member state.