OK, so biofuels have been all the rage for some time, and we've got the farm subsidies to prove it. But now there's something actually promising and -- potentially -- not just a giant boondoggle: biofuels from switchgrass.
First things first. What's switchgrass? From the Department of Energy:
...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. 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.
That is to say this: unlike using corn for fuel, switchgrass doesn't have to remove prime cropland (not to mention actual food crops) from circulation in order to feed our energy needs.
So how does this switchgrass stack up against corn in net-energy-yield? To give a quick if sloppy background, converting corn to ethanol provides embarrassingly little energy gain. To quote the DOE again:
Looking down the road, McLaughlin believes switchgrass offers important advantages as an energy crop. "Producing ethanol from corn requires almost as much energy to produce as it yields," he explains, "while ethanol from switchgrass can produce about five times more energy than you put in. When you factor in the energy required to make tractors, transport farm equipment, plant and harvest, and so on, the net energy output of switchgrass is about 20 times better than corn's." Switchgrass also does a far better job of protecting soil, virtually eliminating erosion. And it removes considerably more CO2 from the air, packing it away in soils and roots.
Looks like we might -- might! -- have a winner. Time will tell.
To read the full release from the DOE, click here.
Labels: biofuel, ethanol, switchgrass