But there are serious challenges:
The program is as complex as it is costly. Nevertheless, success appears to be proving the genetic engineers right. The microbiologists at Joule have created blue algae strains that pump so-called alkanes outward through their membranes. Alkanes are energy-rich hydrocarbons contained in diesel fuel. "You have to persuade the cell that it stops growing and makes the product of interest and does it continuously," Robinson explains. In contrast to ethanol, the end product is not a low-quality fuel, but a highly pure product that contains no sulfur or benzene. "You could put our product in your car," says Robinson.
The laboratory algae are now doing their work in high-tech bioreactors, where carbon dioxide is constantly bubbling through shimmering green panels that look like solar collectors. Robertson's ultimate goal is to derive about 140,000 liters of biofuel a year from one hectare of land -- a yield 40 times as high as with corn grown for ethanol. Joule has bought about 500 hectares of desert land in New Mexico to build a first commercial plant.
Calculations show that some algae plants will likely consume more fertilizer and energy per hectare than grain crops. And the carbon dioxide in the air won't be enough to feed the microalgae. Scientists estimate that a commercial algae fuel plant would require about 10,000 cubic meters of CO2 a day. Whether and how large amounts of the gas could be derived from the exhaust gases of large coal power plants, for example, and then brought to the algae farms, remains unclear.Considering how rapidly the technology is improving, a tripling of productivity seems entirely possible.
The farms could also require enormous tracts of land. In a recent article in the journal Science, researchers at Wageningen University in the Netherlands calculated that, in theory, an area the size of Portugal would have to be filled with algae pools to satisfy Europe's current fuel needs. A "leap in microalgae technology" is needed to at least triple productivity, say experts.