Want the Next Big Energy Source? Dig in the Weeds
SWEDEN: August 21, 2007
STOCKHOLM - Plants that can be grown for fuel are often touted as a vast,
clean energy source -- except by those who say precious food is being
diverted into gas tanks, and that biofuel crops are using up dwindling land
and water.
Enter willow, hemp and switchgrass.
Scientists say research into a new generation of biofuel sources could yield
cheap energy supplies that do not compete with food crops -- or with nature
-- for water or space.
The day may be decades away, but some say plants might even cover a large
share of the world's energy needs.
Goran Berndes, a researcher at Chalmers University of Technology in Sweden,
says the list of possible plants goes far beyond the established crops such
as corn, maize and sugar cane that are already grown commercially for fuel
uses.
"Bioenergy is much broader," he said. "Most people working in bioenergy
expect other crops to dominate in the long term."
One promising energy source is the willow, a northern plant used to make
baskets and sport bats. Others include hemp, known for its rope-making and
mind-altering qualities, and switchgrass, a reedy plant found in the US
Midwest.
A new crop that is being used already is jatropha, a resilient, oil-rich,
tropical plant that can be grown on waste land and even introduces nutrients
to the soil. Its oil is already used in India to power diesel cars and
turbines.
Jatropha has grabbed headlines because it avoids the biggest controversy
surrounding biofuels: the ethical debate over whether agricultural resources
should be used for energy when millions across the planet go hungry.
This can mean using up water as well as land -- a reminder that biofuel
crops themselves can carry severe risks for the environment, especially if
hitherto unfarmed land is converted to agriculture with large amounts of
fertiliser and irrigation.
The International Water Management Institute, which led a five-year global
study on water involving more than 700 researchers, found that if China and
India pursued their current biofuel plans, they faced water scarcity by
2030.
LET IT RAIN
Berndes has built models that try to peer even further into the future,
assuming that crop yields will continue to climb as agricultural science
advances, and new biofuel crops will become more productive.
One scenario -- highly optimistic, perhaps, but theoretically possible --
suggests that an area of agricultural land twice the size of Mexico could
become surplus to current requirements by 2050.
If this were all used to grow biofuels, it could yield 400 exajoules of
energy -- almost the equivalent of the world's current energy consumption.
Of course, such scenarios are hugely complex, and it is not merely a
question of finding enough land.
The assumed higher crop yields are likely to tax the environment harder by
requiring more irrigation and fertilisation. "If you need less land, you
cannot be sure you need less water," Berndes says.
Hence the need to ensure that the new generation of biofuel crops are not
also hungry for scarce resources -- for instance getting their water from
rain rather than irrigation.
And they will need to be commercially attractive.
"You have many different ways of producing transportation fuels from these
new biomass sources that are not there yet commercially," he said.
BUSINESS BUDDIES
At least one business sector is prepared to lobby for biofuel crops that do
not compete so hard with food production.
Nestle, the world's largest food company, says the subsidies being applied
to current biofuel crops are distorting the market and pushing up the prices
of food crops, and that second-generation biofuels could be an answer.
"If it works, and if it can be made to work economically, that certainly
would be -- both from an environmental and from an economic point of view --
a much better solution than this strong focus on the current
first-generation food crop biofuels," said Claus Conzelmann, Nestle vice
president for safety, health and the environment.
But there are those who say the entire debate is misguided.
Vaclav Smil, a professor at the University of Manitoba, says that with
relatively straightforward changes to the cars we drive, we could do without
extra energy altogether.
"I'm astonished that people even think about biofuel," Smil told a
conference in Stockholm. "Do we need more biofuels to feed our cars? We
don't."
Story by Adam Cox
REUTERS NEWS SERVICE
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