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Growing Crops for Fuel: Thanksgiving in the Gas Tank

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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.
DPA

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.

Its remote location—and its modesty make Penkun the ideal place for one of the most impressive sets of structures of the coming post-industrial age. Some 40 concrete vats, each 28 meters (92 feet) in diameter, will take up most of the available space in the local industrial zone, launching the biggest organized digestive process in history. Corn produced on 6,000 hectares (14,826 acres) of farmland, totaling more than 200,000 tons a year, will decompose in the containers the way it would in cows' intestines, emitting methane-containing biogas in the process.

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
Norbert Michalke

The biogas power plant at Penkun, Germany

Although the corn plant in the eastern German state won't exactly be replacing any nuclear power plants at this level, it does mark the first step in an extensive corporate strategy that is expected to transform much of the vegetation in Germany's east into the world's leading source of renewable methane gas. Nawaro AG plans to bring one new electricity factory of the same size on line each year from now on. "But we don't expect to make any money with the first one," explains CEO Balthasar Schramm.

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.

Untapped potential

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 world’s highest-yielding sources of energy, are really just ancient, fossilized forms of biomass.

Graphic: Green Oil Fields
DER SPIEGEL

Graphic: Green Oil Fields

All fuels, whether they occur in the form of a bale of hay, a bundle of wood, propane gas or petroleum, are fundamentally related. Their molecular structure contains carbon and hydrogen, the fundamental building blocks of energy. Even every dandelion is a potential drop of fuel.

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. That’s 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 firm’s 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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