The Latest Breakthrough in Biofuels: Low-Cost Seaweed?

By Katrina Schwartz, KQED Climate Watch

The newest biofuel making a splash is seaweed.

Researchers at Berkeley-based Bio Architecture Lab (BAL) have discovered a way to genetically manufacture a microbe that can break down the sugars in seaweed, so that it can be used as a fuel source. Biofuels from sources other than corn have generated a lot of hype but so far not the large-scale production necessary for them to be considered an integral part of the U.S. energy future (see Lauren Sommer’s recent biofuels “reality check,” for KQED’s QUEST).

There are many kinds of algae. The ones that have received most attention are microalgaes that grow in freshwater ponds. The U.S. Department of Energy has invested heavily in research on microalgaes. Defense officials are looking to oil extracted from the freshwater scum to fuel military machinery. Last week a California Report story highlighted the efforts of researchers in San Diego to scale up production of oil from algae, in order to bring down the cost and make it viable on the energy market.

The Berkeley lab’s discovery has huge implications for converting seaweed to ethanol, a component of gasoline. The engineered microbe can break down the primary sugar in seaweed, alginate, which other microbes could not. Once the sugar is broken down it can be used to make ethanol.

In an article on the breakthrough, The Guardian’s Damian Carrington reports on the potential of seaweed as a fast-reproducing fuel source.


A seaweed farm in Bali, Indonesia. According to one estimate, using just 3% of the Earth's coastal waters to grow seaweed could produce 60 billion gallons of ethanol. Credit: Nikki McLeod/flickr.

The fact that a seaweed industry already exists is a major advantage, said Daniel Trunfio, chief executive at Bio Architecture Lab (BAL) in Berkeley, California, where the research was conducted. “People have been farming seaweed for 1,000 years. In China and Japan, you will see farms that are the equivalent of the midwest cornfields in the U.S.,” he said. “This can be a substantial addition to the fuel portfolio.” He argues that using 3% of the world’s coastal waters to grow seaweed would produce 60 billion gallons of ethanol — more than 40% of the fuel burned by U.S. cars and trucks. His company is backed by the U.S. Department of Energy, Norwegian oil company Statoil and the government of Chile, where BAL owns seaweed farms and is building a pilot plant.

One of the biggest barriers for seaweed-based fuel is the same as for other algae-based fuels: cost. Until researchers can figure out a way to farm, harvest and convert seaweed into ethanol more cheaply, ethanol made from corn or sugarcane will continue to prevail in the marketplace.

KQED Climate Watch, a Climate Central content partner.

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