Henning agrees that it is smart for jatropha growers to start small. Biodiesel cannot compete with current petroleum prices, which are relatively low, so jatropha would be better suited for local projects that improve rural livelihoods and basic energy services. These small projects have already started to build a framework of familiarity and expertise--in parts of Tanzania, kids learn about jatropha in school. Then, as fuel prices increase, jatropha cultivation can go to a larger scale. The wild shrub could then become a "sustainable cash crop," Joos believes, and a fuel for the future.