The jatropha bush seems an unlikely prize in the hunt for alternative energy, being an ugly, fast-growing and poisonous weed. Hitherto, its use to humanity has principally been as a remedy for constipation. Very soon, however, it may be powering your car.
Almost overnight, the unloved Jatropha curcushas become an agricultural and economic celebrity, with the discovery that it may be the ideal biofuel crop, an alternative to fossil fuels for a world dangerously dependent on oil supplies and deeply alarmed by the effects of global warming.
The hardy jatropha, resilient to pests and resistant to drought, produces seeds with up to 40 per cent oil content. When the seeds are crushed, the resulting jatropha oil can be burnt in a standard diesel car, while the residue can also be processed into biomass to power electricity plants.
As the search for alternative energy sources gathers pace and urgency, the jatropha has provoked something like a gold rush. Last week BP announced that it was investing almost £32 million in a jatropha joint venture with the British biofuels company D1 Oils.
Even Bob Geldof has stamped his cachet on jatropha, by becoming a special adviser to Helius Energy, a British company developing the use of jatropha as an alternative to fossil fuels. Lex Worrall, its chief executive, says: “Every hectare can produce 2.7 tonnes of oil and about 4 tonnes of biomass. Every 8,000 hectares of the plant can run a 1.5 megawatt station, enough to power 2,500 homes.”
Jatropha grows in tropical and subtropical climates. Whereas other feed-stocks for biofuel, such as palm oil, rape seed oil or corn for ethanol, require reasonable soils on which other crops might be grown, jatropha is a tough survivor prepared to put down roots almost anywhere.
Scientists say that it can grow in the poorest wasteland, generating topsoil and helping to stall erosion, but also absorbing carbon dioxide as it grows, thus making it carbon-neutral even when burnt. A jatropha bush can live for up to 50 years, producing oil in its second year of growth, and survive up to three years of consecutive drought.
In India about 11 million hectares have been identified as potential land on which to grow jatropha. The first jatropha-fuelled power station is expected to begin supplying electricity in Swaziland in three years. Meanwhile, companies from Europe and India have begun buying up land in Africa as potential jatropha plantations.
Jatropha plantations have been laid out on either side of the railway between Bombay and Delhi, and the train is said to run on more than 15 per cent biofuel. Backers say that the plant can produce four times more fuel per hectare than soya, and ten times more than corn. “Those who are working with jatropha,” Sanju Khan, a site manager for D1 Oils, told the BBC, “are working with the new generation crop, developing a crop from a wild plant — which is hugely exciting.”
Jatropha, a native of Central America, was brought to Europe by Portuguese explorers in the 16th century and has since spread worldwide, even though, until recently, it had few uses: malaria treatment, a windbreak for animals, live fencing and candle-mak-ing. An ingredient in folk remedies around the world, it earned the nickname “physic nut”, but its sap is a skin irritant, and ingesting three untreated seeds can kill a person.
Jatropha has also found a strong supporter in Sir Nicholas Stern, the government economist who emphasised the dangers of global warming in a report this year. He recently advised South Africa to “look for biofuel technologies that can be grown on marginal land, perhaps jatropha”.
However, some fear that in areas dependent on subsistence farming it could force out food crops, increasing the risk of famine.
Some countries are also cautious for other reasons: last year Western Australia banned the plant as invasive and highly toxic to people and animals.
Yet a combination of economic, climatic and political factors have made the search for a more effective biofuel a priority among energy companies. New regulations in Britain require that biofuels comprise 5 per cent of the transport fuel mix by 2010, and the EU has mandated that by 2020 all cars must run on 20 per cent biodiesel. Biodiesel reduces carbon dioxide emissions by nearly 80 per cent compared with petroleum diesel, according to the US Energy Department.
Under the deal between BP and D1, £80 million will be invested in jatropha over the next five years, with plantations in India, southern Africa and SouthEast Asia. There are no exact figures for the amount of land already under jatropha cultivation, but the area is expanding fast. China is planning an 80,000-acre plantation in Sichuan, and the BPD1 team hopes to have a million hectares under cultivation over the next four years.
Jatropha has long been prized for its medicinal qualities. Now it might just help to cure the planet.
– D1 Oils, the UK company leading the jatropha revolution, is growing 430,000 acres of the plant to feed its biodiesel operation on Teesside — 44,000 acres more than three months ago, after a huge planting programme in India. It has also planted two 1,235-acre trial sites this year in West Java, Indonesia. If successful, these will become a 25,000-acre plantation. Elloitt Mannis, the chief executive, says that the aim is to develop energy “from the earth to the engine”.
Jatropha: costs and benefits
– Jatropha needs at least 600mm (23in) of rain a year to thrive. However, it can survive three consecutive years of drought by dropping its leaves
– It is excellent at preventing soil erosion, and the leaves that it drops act as soil-enriching mulch
– The plant prefers alkaline soils
– The cost of 1,000 jatropha saplings (enough for one acre) in Pakistan is about £50, or 5p each
– The cost of 1kg of jatropha seeds in India is the equivalent of about 7p. Each jatropha seedling should be given an area two metres square.
– 20 per cent of seedlings planted will not survive
– Jatropha seedlings yield seeds in the first year after plantation.