Aquarium scum: fuel of the future

BORCULO, Netherlands -- Set amid cornfields and cow pastures in eastern Holland is a shallow pool that is rapidly turning green with algae, harvested for animal feed, skin treatments, biodegradable plastics — and with increasing interest, biofuel.

In a warehouse 200 kilometers southwest, a bioreactor of clear plastic tubes is producing algae in pressure-cooker fashion that its manufacturer hopes will one day power jet aircraft.

Experts say it will be years, maybe a decade, before this simplest of all plants can be efficiently processed for fuel. But when that day comes, it could go a long way toward easing the world's energy needs and responding to global warming.

Algae is the slimy stuff that clouds your home aquarium and gets tangled in your feet in a lake or ocean. It can grow almost everywhere there is water and sunlight, and under the right conditions it can double its volume within hours. Scientists and industrialists agree that the potential is huge.

"This is the ultimate fast-growing organism," says Peter van den Dorpel, chief operating officer of AlgaeLink, which makes bioreactors for speeding reproduction. "Algae is lazy. It eats carbon dioxide and produces oxygen." It has no roots, no leaves, no shoots. "It grows so fast because it has nothing else to do. It just swims in the water."

Farming algae doesn't require much space or good cropland, so it avoids the fuel-for-food dilemma that has plagued first and second generation biofuels like corn, rapeseed and palm oil.

It can grow in fresh water, polluted water, sea water or farm runoff. It can purify a city's sewage while feeding on the nitrogen and phosphates in human waste.

And it is rich in oil. The most common types farmed today have an oil content of 30%, and it can go up to 70% or more.

It also consumes nearly twice its weight in carbon dioxide, the most common greenhouse gas that is discharged by vehicles, power plants and many heavy industries and which scientists say is causing climate change.

Seeking to cut its carbon emissions, the European Union last year mandated that 20% of Europe's energy must come from renewable sources by 2020, up from 8.5% now. Originally, that plan called for a 10% biofuel component for road transportation, but pressure on food supplies prompted a key EU parliamentary committee to vote to scale back that target by as much as half.