LONDON — Record high world food prices threaten to limit the use of land for low-carbon energy crops just as British efforts to pioneer growth of the giant grass miscanthus in Europe are poised to gather pace.
Miscanthus giganteus is an Asian elephant grass that grows 3 meters, or 10 feet, high and whose tawny leaves are now at their tallest, before harvest time next month. The grass is being promoted alongside willow, sawdust and straw as biomass for producing heat and power when burned, without causing net emissions of the greenhouse gas carbon dioxide.
Burning biomass returns to the atmosphere the same carbon dioxide that the plants took in when they were growing and so can cut net emissions compared with fossil fuels.
Miscanthus needs little or no manufactured fertilizer and is harvested annually over a 15- to 20-year period.
“It is a beast of a crop,” said one former grower, Ross Dickinson, based in the southwest of England, referring to its prolific output. “After establishment, apart from cutting it down and baling it, there are no input costs.”
In the future, miscanthus may also be a critical feedstock for a new generation of liquid transport fuels made from nonfood crops.
Britain is leading trials of the crop in Europe, with harvests growing more than tenfold in the past five years to an area twice the size of Manhattan Island in New York, government data show. That could expand more quickly as the country tries to meet ambitious E.U. targets for renewable energy.
“I applaud it,” said Peter Harper, head of research and innovation at the Center for Alternative Technology in Wales, although adding that achievements so far are still limited.
“It’s a drop in the ocean of what we need,” he said. “We need experience.”
Britain told the Union last year that it had a “theoretical potential” to plant 7,000 square kilometers, or 2,700 square miles, of miscanthus and other woody crops by 2020, about 4 percent of the country’s farmed area, to help meet its clean energy goals.
Also driving adoption in Europe are rising penalties on the emissions of carbon dioxide from burning of fossil fuels. All power generators in Western Europe will have to buy a permit for every ton of carbon dioxide emissions beginning in 2013.
“We’re looking to see how we can increase the amount of biomass that we burn,” said Rob Wood, buyer at the Drax coal plant, which is the biggest carbon emitter in Britain.
Mr. Wood said that since the summer of 2009, the plant had entered into contracts with at least 100 growers within a 100-mile radius of the Drax power station for the supply of miscanthus.
Drax has the world’s biggest coal and biomass co-burning facility, which is able to use 1.4 million tons a year of plant material to drive a steam turbine and generate electricity.
Britain is promoting energy crops under a program to meet a binding E.U. commitment to get 15 percent of its energy from renewable sources by 2020, compared with about 3 percent now.
Growth may be limited by concerns that the project will compete with food crops, however, especially as Britain has limited land.
Last month, the global food price index charted by the United Nations reached record levels, and the use of crops to produce energy has raised questions over competition for land. The U.N. food price agency said last week that main prices for grain could climb yet further as weather patterns gave cause for concern.
Drax said it would not sign contracts with farmers who were planning to convert from cereals like wheat and added that miscanthus was unlikely to be economic on high-grade land, given the elevated prices for grain.
“Landowners in more densely populated centers will inevitably find more profitable uses for their land,” said Peter Sharratt, at the consulting firm WSP Environment & Energy.
“This makes biomass far less viable and raises some serious sustainability issues as we displace local food production in favor of energy cropping or create a new dependency on large-scale biomass imports.”
WSP calculated that planting energy crops on a fifth of Britain’s arable land would meet just 10 percent of the British heating demand.
Similar concerns have been long expressed over the huge market in transport biofuels, produced from food crops including corn, sugar and oilseed. About 40 percent of the U.S. corn crop is currently used to make ethanol to power cars.
Experts said new British planting of miscanthus was disappointing last year, reflecting poor awareness among farmers, while the big British producer Bical went bankrupt in 2009, partly because of unpredictable government support.
Better promotion among farmers is needed, said Mike Cooper, commercial manager at Renewable Energy Crops, which has contracts with about 400 British farmers to grow miscanthus.
“If government only said that they needed perennial energy crops. Farmers understand that there’s a demand for food, but no one’s making plain that there’s a demand for energy crops.”