Miracle Biofuel Plant Jatropha Reveals Its Achilles Heel

Last Updated Jun 9, 2009 7:58 AM EDT

Jatropha, a hardy, drought resistant plant that grows oil-heavy fruit, was supposed to be the salvation of the biodiesel industry. The plant, which was targeted for an $80 million pilot project by BP and D1 Oils, can grow on marginal lands that crops don't like. It tends to favor a land type that is common in developing countries like China and India, as well as many African nations, giving them a much-needed edge. Its fruit can be up to 40 percent oil, making it an excellent energy source.

But jatropha is also new to cultivation, and planters are still figuring out how to effectively grow the plant. Predictably enough, they're finding out that rosy initial estimates on how well the plant would do may have been vastly overblown. The biggest problem by far is the amount of water the plant consumes, according to a study covered in MIT's Technology Review.

A single liter of jatropha biodiesel requires a whopping 20,000 liters of water to grow, say researchers at the Netherlands' University of Twente. That's more than canola, corn, soybeans or sugarcane -- more, in fact, than any commonly used biofuel crop. The two closest, canola and soybeans, require about 14,000 liters each.

The irony of jatropha's water needs is considerable, since the plant is supposed to be a godsend for arid land that doesn't get much rainfall. The report suggests that jatropha does just fine without much water, but only produces bumper crops when it has plenty to drink, much like any other plant.

How much of a problem will the water requirements be for the burgeoning jatropha industry? Possibly not as much as it might seem at first glance. Irrigation of dry land is practiced around the world at massive scales, so the barrier is not technical. However, sucking up all the water available in a locality will pit jatropha against food crops and people, putting it in the same boat as ethanol from corn.

Yields from jatropha may also be only a quarter of some estimates, so the economics of the plant may not be as incredible as first thought, either. What those are, exactly, will be revealed only later by the success of a first generation of companies like Galten Biofuels, Jatoil and the BP partnership.

And finally, there's also hope that jatropha will mature into a better biofuel producer. Any plant new to cultivation takes a period of time before it reaches an optimum tame form, and jatropha has only been in use for a few years. There are also companies like SG Biofuels, covered here a couple months ago, that are performing gene research on jatropha in hopes of extending its range and improving its yield.