Green gold losing its glitter to be?

“This year, a lot of projects did not continue,” admits Thilo Zelt, director of the Jatropha Alliance.

One blow came with the publication of a controversial paper in June, in which a team led by Arjen Hoekstra at the University of Twente in the Netherlands suggested that jatropha needs more water than other bioenergy crops, such as maize (corn), to produce the same amount of oil.

Jatropha had nearly four times the water footprint of sugar-cane ethanol, for instance.

Critics point out what they see as flaws in that analysis, including the fact that it is difficult to compare jatropha, which is wild, with crops such as maize that were domesticated for optimal use thousands of years ago.

In addition, the analysis looked at a small number of plantations, all of which had young trees, which could skew the conclusions, says Bart Muys, a forest ecologist at the University of Leuven in Belgium.

But Hoekstra says that more thought needs to be given to variables such as where jatropha is planted and how it is harvested.

“Jatropha was the hallelujah crop,” he says, but in reality “it is just another crop with its own characteristics”.

The split between D1 Oils and BP has hurt jatropha’s reputation as a good business investment, says Boyle.

In a statement, BP spokeswoman Sheila Williams said that “the decision to pull out of this is purely based on economics and a decision to focus on key strategic areas”, such as sugar-cane ethanol from Brazil, cellulosic ethanol from the United States and biobutanol.

In the meantime, D1 Oils has shifted from planting jatropha to focusing on basic research — including starting a breeding programme to develop seeds with high oil yields, says Henk Joos, the company’s head of plant science.

Another company concentrating on basic science is SG Biofuels, based in Encinitas, California.

It has collected samples from jatropha plants growing wild in different environments and is creating a library of genetic material from which it intends to develop enhanced seed strains to test, says chief executive Kirk Haney.

Eventually, Jatropha might prove more useful on a local scale.

For instance, Diligent Energy Systems, a company based in Eindhoven, the Netherlands, has set up small-scale operations in Tanzania, where it provides jatropha seeds for farmers to plant among other crops or on spare land that is unsuitable for food crops.

The farmers are guaranteed a price for the oil seeds they produce, and so have an incentive to tend the crop and harvest it carefully, says company founder Ruud van Eck.