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 fertilizer 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.
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 fertilization. "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.
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." –
Reuters
