Fuelling the future

With over six billion people and 600m cars in the world today, the global energy requirement is skyrocketing. Add to that increased pressure from international initiatives such as the Kyoto Agreement to reduce carbon emissions and the lobbying activities of environmental pressure groups, and it's clear that governments have a tough challenge on their hands.

Over the past 30 years, governments world-wide have been investigating renewable energy sources. The use of crops or waste as an efficient, cost-effective, locally-available and sustainable source of energy has increased, bringing opportunities for farmers and governments alike while also benefiting the environment.

Larger scale or nation-wide initiatives include the Indian government investigating a fast-growing and oil-rich small plant Jatropha curcas (physic nut) as part of its drive to switch over to gasohol - petrol laced with five per cent ethanol - in nine states. Similarly, Indian Railways switched to five per cent biodiesel (planned eventually to rise to 20 per cent) in its 4000-plus trains this year. As the company uses around five per cent of the 38m tonnes of diesel used in India every year, it is hoped that this will lead to a significant decrease in carbon dioxide and particulate output as well as reducing pressure on foreign exchange reserves - a large part of which are used to purchase the country's crude oil requirement.

However, just using crops to make biodiesel or bioethanol to fuel cars or railways isn't enough, says Donna Clarke, director of business development at UK-based Greenergy which supplies low emission fuels to a number of European markets. "You need to look into the overall environmental, social and economic sustainability of the production of those energy crops and the processes needed to turn them into fuel. For example, palm oil biodiesel is produced in Malaysia and Indonesia, but is heavily subsidised and is therefore not sustainable," she told New Agriculturist.

"You need to look at the benefits of the 'biofuel' against those of standard fuels," she said. For example, there is no point growing sugar beet as an energy crop if it requires lots of inputs and resources to grow, she said. "You would be better off making bioethanol from waste and growing rapeseed for biodiesel."

Greenergy currently sells its GlobalDiesel - a blend of five per cent renewable biodiesel and 95 per cent ultra low sulphur diesel - from just three outlets in the UK. It sources rapeseed-based biodiesel on the open market, but is presently using biodiesel made from oilseed rape grown in France and Germany. "We are currently only buying biofuels from EU member countries because that is the only way we can guarantee a non-GM product," she said. "We don't buy any soya for that reason too." Countries like Australia and those in the EU tend to use an 85 or 50 per cent blend of bioethanol (produced from sugar) mixed with standard fuels. For a vehicle to use 100 per cent bioethanol it has to have a specially converted engine, she explained.

Ms Clarke also said that claims of dramatic reductions in greenhouse gas emissions through the use of 'biofuels' were often unjustified. "We are very concerned about the way some things are presented. Different sources of production have different carbon balances, so it is not always true that just because a fuel is produced from crops, it is 100 per cent environmentally friendly," she said.

Examples of smaller scale schemes that make use of crops or by-products for fuel include sugar mills converting their waste (bagasse) into energy to fund their own electricity requirements, and in some cases, producing a surplus to sell to the national grid. One such example is the San Antonio sugar mill near Chichigalpa in the north-western region of Nicaragua - the largest sugar mill in the country. During the sugarcane season it generates its own power from bagasse and from eucalyptus grown in dedicated energy plantations at other times of the year. The mill's double role of energy user and energy producer creates environmental and socio-economic benefits - employment in the mill is now year-round rather than seasonal as it was previously. "From the technical point of view, the approach taken at the San Antonio sugar mill is replicable in most sites in the sugar producing tropics," the FAO's Dr Gustavo Best said in his report on the project. "Adjustments would have to be made, but no main barrier is foreseen."

Energy crop production in the 'north' is primarily driven by environmental motives and is supplementary to conventional power generating methods, while in developing countries it is seen as a more viable way of meeting local energy demands. Therefore, the opportunities for farmers to grow crops for energy vary across the world. For those in developing countries, those opportunities may depend more on small-scale high energy demanding industrial or processing development, rather than national energy policies. Either way, crops and their by-products can be used to good effect as a sustainable source of energy while also stimulating markets and local employment and cutting global pollution.

For further information see Greenergy's website