The U.S. Department of Energy (DOE) believes that biofuels — made from crops of native grasses, such as fast-growing switchgrass—could reduce the nation's dependence on foreign oil, curb emissions of the "greenhouse gas" carbon dioxide, and strengthen America's farm economy. The Biofuels Feedstock Development Program (BFDP) at DOE's Oak Ridge National Laboratory (ORNL), has assembled a team of scientists ranging from economists and energy analysts to plant physiologists and geneticists to lay the groundwork for this new source of renewable energy. Included are researchers at universities, other national laboratories, and agricultural research stations around the nation. Their goal, according to ORNL physiologist Sandy McLaughlin, who leads the switchgrass research effort, is nothing short of building the foundation for a biofuels industry that will make and market ethanol and other biofuels from switchgrass and at prices competitive with fossil fuels such as gasoline and diesel.
The American prairie — tens of millions of acres — was once covered with tall fast-growing native grasses that fed millions of bison. Switchgrass is one of America's natural prairie grasses.
Switchgrass grows fast, capturing solar energy and turning it into chemical energy in the form of cellulose that can be harvested and converted to sugar.
Switchgrass reaches deep into the soil for water, and uses the water it finds very efficiently. The plant can thrive in climates and growing conditions spanning much of the nation.
Switchgrass can be cut and baled with standard farming equipment.
Many farmers are already experienced at raising switchgrass for forage or to protect soil from erosion. Switchgrass also restores vital organic nutrients to farmed-out soils.
Test plots of switchgrass at Auburn University have produced up to 15 tons of dry biomass per acre, and five-year yields average 11.5 tons — enough to make 1,150 gallons of ethanol per acre each year.
— Scientists determine farm costs of producing switchgrass for ethanol (With the total farm costs of growing switchgrass known, scientists have estimated the cost of producing cellulosic ethanol from switchgrass will be about $0.55 to $0.62 per gallon) April 11, 2008
First, a distinction: switchgrass and your suburban lawn grasses — bluegrass and zoysia grass — are about as similar as a shopping-mall ficus and an old-growth redwood. Switchgrass is big and it's tough — after a good growing season, it can stand 10 feet high, with stems as thick and strong as hardwood pencils.
Switchgrass can be harvested using conventional farm equipment.
But what makes switchgrass bad for barefoot lawns makes it ideal for energy crops: It grows fast, capturing lots of solar energy and turning it into lots of chemical energy — cellulose — that can be liquified, gasified, or burned directly. It also reaches deep into the soil for water, and uses the water it finds very efficiently.
And because it spent millions of years evolving to thrive in climates and growing conditions spanning much of the nation, switchgrass is remarkably adaptable.
Now, to make switchgrass even more promising, researchers across the country are working to boost switchgrass hardiness and yields, adapt varieties to a wide range of growing conditions, and reduce the need for nitrogen and other chemical fertilizers. By "fingerprinting" the DNA and physiological characteristics of numerous varieties, the researchers are steadily identifying and breeding varieties of switchgrass that show great promise for the future.
Many farmers already grow switchgrass, either as forage for livestock or as a ground cover, to control erosion. Cultivating switchgrass as an energy crop instead would require only minor changes in how it's managed and when it's harvested. Switchgrass can be cut and baled with conventional mowers and balers. And it's a hardy, adaptable perennial, so once it's established in a field, it can be harvested as a cash crop, either annually or semiannually, for 10 years or more before replanting is needed. And because it has multiple uses — as an ethanol feedstock, as forage, as ground cover — a farmer who plants switchgrass can be confident knowing that a switchgrass crop will be put to good use.
Research farms have demonstrated that switchgrass farming can yield about 1,000 gallons of ethanol per acre each year:
- One thousand acres of switchgrass would yield about one million gallons of ethanol per year.
- One million acres of switchgrass would yield about one billion gallons of ethanol annually.
- One hundred million acres of switchgrass could produce about one hundred billion gallons of ethanol every year.
The deep Switchgrass root system could store tons of atmospheric carbon - removing the cause of global warming.
“Switchgrass could have a lot to do with carbon sequestration storage potential and for overall improvement of soil quality as well,” says Mark Liebig, a soil scientist at USDA's Agricultural Research Service laboratory in Mandan.
— Biofuels from Switchgrass: Greener Energy Pastures (Oak Ridge National Laboratory, Bioenergy Feedstock Development Program)