A few weeks ago, ExxonMobil announced a commitment to invest $300 million over five to six years in Synthetic Genomics, which the famous scientist Craig Venter founded and now leads as CEO, and to spend an additional $300 million on a complementary internal algae program. Here’s more about this new investment.

The push is to take advantage of algae’s ability to efficiently transform sunlight into lipids that can be relatively easily converted into diesel, gasoline, and possibly even advanced hydrocarbons used to manufacture plastics, chemicals, and other products.

By the barrel, algae fuel provides three to four units of energy for every unit used to make it–a ratio that approaches petroleum’s 5-to-1 level of efficiency. The ratio for making ethanol from corn is a mere 1.2 to 1, according to some studies. Even making ethanol from cellulosic plants like switchgrass, researchers can achieve only a 2.5 to 1 ratio.

Venter’s company has been developing strains of bioengineered algae that ramp up the output of lipids and can in some cases produce hydrocarbons directly. However, Venter and Emil Jacobs, senior vice president for R&D at ExxonMobil Research and Engineering, both emphasize that their companies will collaborate to investigate any viable option to push algae into the big time of energy sources.

Since research in algae fuels began in the 1970s at the Department of Energy–as part of President Jimmy Carter’s efforts to develop alternative fuels after the oil shocks of that era–several methods have emerged.

First is an open-pond system that grows algae out in the sun. Another is a closed, sunless system that feeds carbon from feed stock such as sugarcane to algae plants in fermentation tanks. A third type is a closed-system bioreactor that uses sunlight.