Growing Crops for Fuel: Thanksgiving in the Gas Tank
Are plants the power source of the future? Biomass could be one solution to our dependency on fossil fuels. Though biodiesel from rapeseed and alcohol from grains are uneconomical and hardly less harmful to the environment than gasoline, second-generation production methods are now fueling a new optimism.
German rapeseed fields: The German government estimates that by 2020, amost one-third of the country's arable land could be used for the production of energy crops.
The town is Penkun, a humdrum little place in southeastern Western Pomerania. It's the last Autobahn exit before the Polish border, a green spot in the middle of nowhere, surrounded by seemingly endless fields.
The artificially produced intestinal gas is a high-quality fuel and will drive an array of 40 six-foot-tall, 12-cylinder motors, which in turn will produce electricity through generators. Nawaro AG, the operator of what will be the world's most productive biogas power plant, plans to have all the cylinders up and running at the first facility by late summer of this year. From then on, they will supply the German power grid with a constant stream of 20 megawatts of electricity.
The biogas power plant at Penkun, Germany
Long ignored, the biomass sector is suddenly taking center stage in the heated controversy over alternative energies. Even the name sounds clumsy and not exactly futuristic, unlike shimmering solar cells and sterile laboratories. Indeed, biomass is more likely to evoke images of a rubber-booted country bumpkin, stoically trudging through a mass of soupy, decomposing plant matter.
Biomass is as old as life on Earth. It's the storage system for solar energy in the cycle of terrestrial life. Man has been using it as a fuel for more than 1.5 million years. Yet in all that time, he has failed to do anything more than simply burn it. In fact, petroleum, natural gas and coal, the worlds highest-yielding sources of energy, are really just ancient, fossilized forms of biomass.
Graphic: Green Oil Fields
A very rough guesstimate of the earth's fertile land reveals the sheer potential of biomass. According to an estimate by the United Nations Food and Agricultural Organization (FAO), the world's 6.5 billion people have about 5 billion hectares (about 12.35 billion acres) of developed farmland and pasture at their disposal. Meat eaters living a Western lifestyle require about 10 hectares (24.7 acres) to feed 25 people. Vegetarians need only about one-tenth as much land.
But even in a world populated by carnivores, this would still leave about 2.4 billion hectares (5.9 billion acres) of land that could be used to produce fuel -- a virtually inexhaustible oil field.
The highest annual yield per hectare from energy-producing plants is about 20 tons of dry plant matter. Thats the equivalent of about 9,000 liters (2,370 gallons) of petroleum.
Even cautious forecasters are optimistic. Indeed, according to a study conducted by Michael Weitz, a Hamburg agricultural scientist, biomass could satisfy the world's entire demand for petroleum, currently about 3.78 billion tons a year.
Global consulting firm McKinsey & Co. also analyzed biomass's potential as an energy supply and reached similar conclusions. According to the consulting firms experts, the availability of plants as a raw material is "not the limiting factor." Instead, a lack of operating biomass refineries is, in the short term, hindering growing demand, says Jens Riese, a McKinsey biochemist and biomass expert.
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