Algae-based fuel is a step closer to reality. Scientists in California have genetically modified a microbe so that it can convert seaweed into biofuel, the Guardian reports. "Natural seaweed species grow very fast—10 times faster than normal plants—and are full of sugars, but it has been very difficult to make ethanol by conventional fermentation," says a researcher. The microbe breakthrough is a "critical step" toward an alternative form of ethanol, but there's still a long way to go.
"Scaling up processes using engineered microbes is not always easy. They also need to prove the economics work," the scientist adds. That could be tough: "The costs are still five times higher than they need to be to get to a reasonable fuel price," says another expert. Still, an abundance of existing seaweed farms offers promise for the future. "In China and Japan, you will see farms that are the equivalent of the Midwest cornfields in the US," says a researcher involved. Some 3% of coastal waters worldwide could provide enough ethanol to supply more than 40% of US drivers' needs, he notes. (Read more seaweed stories.)