Play Live Radio
Next Up:
0:00 0:00
Available On Air Stations

Switch Grass: Alternative Energy Source?


In the president's State of the Union address last night, he talked about new technologies to replace oil imports. And here's something that caught our ears, something we're pretty sure has never snuck into a State of the Union before.

President GEORGE W. BUSH: We'll also fund additional research in cutting-edge methods of producing ethanol, not just from corn, but from wood chips and stalks or switch grass.

BLOCK: Switch grass. We figured we should learn more about it, so we called switch grass expert David Bransby. He's originally from South Africa. He's a professor of energy crops at Auburn University in Alabama, where he grows switch grass.

Dr. DAVID BRANSBY (Auburn University): Switch grass is a tall, what we call a bunch grass. It grows erect; it grows up to eight to nine feet tall. It is native to the United States, which, of course, is very attractive to our environmentalists. They like to see us using native plants rather than introduced plants or what they call exotic plants.

BLOCK: As a native grass, where would it grow?

Dr. BRANSBY: It grows throughout the United States. It has, for any plant species, it has a remarkable range of climatic tolerance, so there are varieties that grow along the Gulf Coast and there are other varieties that'll grow right up into Canada.

BLOCK: And why is switch grass considered good for -- as a potential fuel source?

Dr. BRANSBY: Well, basically, to produce energy from any crop, the key thing is to produce the crop cheaply and in order to get a low cost per ton, the first thing you need is a high yield per acre and then low production costs and that's what switch grass does the best for us right now. You can get yields of between five and 10 tons per acre with very low fertilizer costs and so that's why it is so attractive compared to other options.

BLOCK: Well, say you're getting 10 tons of switch grass per acre and you convert that to ethanol. How many gallons of fuel would you end up with?

Dr. BRANSBY: The best technologies that I know of right now are predicting at least 100 gallons of ethanol per ton, so that would convert to 1,000 gallons of ethanol per acre.

BLOCK: Is that a lot?

Dr. BRANSBY: That is high. Yeah, let's just say what does ethanol sell for? Let's say $1.50. That works back to $1,500 per acre. There are no crops in this country that can do that right now.

BLOCK: And one of the benefits, as I understand it, is that in producing fuel this way, you are essentially recycling carbon dioxide.

Dr. BRANSBY: That's exactly right. Plants absorb the carbon from the atmosphere as carbon dioxide and then once you actually produce the fuel and burn that fuel, it just sends that carbon dioxide back up into the atmosphere.

BLOCK: In one of the complaints about ethanol is that it can take more energy to produce it, if you're growing a crop, than you actually get out of it. Is that a problem also with switch grass?

Dr. BRANSBY: It used to be a problem with corn to ethanol. It is not even a problem there anymore. But with switch grass, it's very different. Inputs are very much lower and we use the whole plant, not just grain. Therefore, the estimates that we have for energy in versus energy out is about, for one unit of energy in, we get about four units of energy out in the form of ethanol.

BLOCK: Do you have any idea how switch grass made it into the State of the Union? What lobby or interest group was putting it in there?

Dr. BRANSBY: Well, our Senator Sessions from Alabama.

BLOCK: Was it Senator Jeff Sessions from Alabama?

Dr. BRANSBY: Correct, yes. Now I had a call from his office on Monday. Then had a few e-mails go backwards and forwards, and I just got one right before you called to say it was a last minute inclusion in the speech and it was Senator Sessions that helped get it into there.

BLOCK: Well, Professor Bransby, thanks very much for talking to us about switch grass today.

Dr. BRANSBY: You're very welcome.

BLOCK: David Bransby, professor of energy crops at Auburn University in Auburn, Alabama. Incidentally, Jeff Sessions's press secretary told us the Alabama Senator had indeed sung the praises of switch grass last Friday in a meeting with Al Hubbard, an economic advisor to the president. Transcript provided by NPR, Copyright NPR.