Is it possible to evolve or modify naturally occurring strains of algae so they will efficiently produce fuel directly from sunlight? Dozens of companies are working toward the goal of creating "superalgae" able to perform this feat.
“There are probably well over 100 academic efforts to use genetic engineering to optimize biofuel production from algae,” said Matthew C. Posewitz, an assistant professor of chemistry at the Colorado School of Mines, who has written a review of the field. “There’s just intense interest globally.”
Algae are attracting attention because the strains can potentially produce 10 or more times more fuel per acre than the corn used to make ethanol or the soybeans used to make biodiesel. Moreover, algae might be grown on arid land and brackish water, so that fuel production would not compete with food production. And algae are voracious consumers of carbon dioxide, potentially helping to keep some of this greenhouse gas from contributing to global warming.
Some concerns about genetically altering algae have been raised by scientists; algae serves a variety of functions on Earth, including providing about 40% of the world's oxygen. However, most scientists dismiss concerns about superalgae that might outcompete natural strains.
Even regular algae can be cultivated to produce biofuel. Take a look at this video describing the Vertigro process.
In his 1950 novel Needle, Hal Clement wrote about culture tanks that would accomplish this feat:
"They call 'em culture tanks. They have bugs -- germs -- growing in them; germs that eat pretty near anything, and produce oil as a waste product. That's the purpose of the whole business. We dump everything that's waste into the tanks, pump the oil off the top, and every so often clean the sludge out of the bottom -- that's a nasty job."
(Read more about Hal Clement's culture tank)