Energy Crop Conundrum

Dedicated energy crops hold massive potential as a renewable energy resource, but hurdles remain in the path of their large-scale utilization.
By Lisa Gibson
A demonstration-scale facility in Vonore, Tenn., began producing cellulosic ethanol in late January, fueled by a steady diet of corncobs with the intent to transition to 100 percent switchgrass feedstock over the next year. The plant has a nameplate capacity of 250,000 gallons and has its biomass supply chain ready and waiting, through the farmer-owned Tennessee Biomass Supply Co-op.

The plant, developed by partners DuPont Danisco Cellulosic Ethanol LLC and Genera Energy LLC, is one of only a few, however, as dedicated energy crops search for their window to permanently and significantly slip into the U.S. renewable energy market. Two crucial steps in the realization of their potential seem obvious: farmer involvement and land-use patterns.

Farmers in the Tennessee Biomass Supply Co-op will be responsible for providing switchgrass to the Vonore facility, including growing, material handling, pre-processing, supply chain logistics and even marketing, according to Kelly Tiller, president and CEO of Genera Energy, wholly owned by the University of Tennessee. "That's the very important next step: getting farmers engaged and involved in the supply chain," Tiller says. "We've set this up as a demonstration for how to do this."

Members of the co-op currently contracted with the University of Tennessee to grow switchgrass for Genera have 2,700 acres planted on private farms. In April, the company will add another 5,000 acres to its cache for use in several of its ongoing projects. "It will actually be in great excess of what we need to operate that facility," Tiller says of the DDCE plant. Switchgrass is a sustainable feedstock that can be used for numerous projects in the Southeastern U.S., she adds. "We actually evaluated a number of different feedstock alternatives and decided that switchgrass was a really good fit for this project and for this region," she says. "We see switchgrass activity as generating a lot of the important values and data we need to develop a commercial-scale supply chain." The U.S. DOE has identified it as a preferred dedicated energy crop and has also determined hybrid poplars and hybrid willows to be favorable tree energy crops for biopower.

Switchgrass is perennial and grows well on marginal and underutilized lands, requires minimal input and can be harvested and handled using existing equipment. The crop's greatest potential is the amount of biomass it can produce, Tiller says, adding that the yield per acre is between eight and 10 tons without improvements in the varieties. Genera, however, will continue work to improve the yield and cost efficiency of the crop.

"In my opinion, [energy crops] hold tremendous potential," Tiller says, being careful to add that they're not the only solution in the world's transition from fossil fuels. A whole portfolio of technologies will come into play. "But within cellulosic ethanol, I do think dedicated energy crops are critical to the large-scale expansion," she says. The Vonore facility will serve to prepare DDCE's integrated conversion technology for commercial production by 2012.

Genera's 7,000 acres are only the tip of the iceberg in switchgrass planting potential in Tennessee. "We did some modeling, looking at marginal cropland just in Tennessee and identified more than 1 million acres that can move into dedicated energy crop production," Tiller says.


Land-use patterns will need to change to accommodate the widespread growth of dedicated energy crops, according to Mark Downing, agricultural economist and senior scientist at the DOE's Oak Ridge National Laboratory in Tennessee. "The biggest resource we have is land," he says. "There may be some limited feedstock issues unless we make some monumental changes about what we do with the land that we have."

Food and energy crops can be grown without interfering with each other, but an in-depth look at all the nation's land resources is essential to optimize agriculture and energy policy, Downing says. The U.S. is good at balancing food, feed and fiber, he adds, but hasn't gotten into the fuel equation yet. "Pick and choose your land for energy crops," he emphasizes. "They don't need No. 1 corn land."

Work also needs to be done to determine where each crop would grow best, a project Ceres Inc. has been working on with its switchgrass, miscanthus, sweet sorghum, biomass sorghum and energy cane varieties. The company's high-yielding switchgrass cultivars and high-biomass sorghum hybrids are available now under the brand name Blade Energy Crops. The company's Web site ( includes maps of the U.S. that outline target markets for each of its crops. Ceres is also evaluating international markets, according to the site. As of now, production of biofuels has been largely limited to the Corn Belt, but the USDA estimates 60 million acres in the nation could be used for dedicated energy crop growth, opening the door to more states participating in biofuels production.

Getting farmers engaged in the supply chain and growing those crops isn't easy, however, and is exacerbated by a lack of standards for biomass conversion technologies. "The farmers are asking the biorefinery what it wants and the biorefinery is asking the farmers what they have," Downing explains, adding that the nation is moving closer to solving the problem, but isn't there yet. "So, I don't have a commodity called biomass that can be assigned value-added properties that make it high enough value to be able to ship it very far." Grain elevators know what they've got when the product comes in, he says. "I want a biomass that looks like grain, handles like grain, is treated like grain. That's my goal."

In order to plant on a large scale, the correct seed varieties and plant materials need to be available, Downing says, making aggressive breeding programs fundamental. Mendel Biotechnology is working to accelerate improvement in plant varieties, drawing on its knowledge of the regulation of plant gene and pathway function. The company serves agricultural companies with new genetic and chemical solutions and strives to be the leading seed company serving the bioenergy industry, according to Mendel.

Another huge barrier to widespread use of dedicated energy crops is the cost of producing cellulosic ethanol. "The trick is yes, you can make ethanol out of lignocellulosic material and it has been done," Downing says. "The problem is you can't afford to do it." Separation of lignin, cellulose and hemicellulose, along with the conversion of cellulose and hemicellulose to sugars for fermenting is a costly endeavor. "You'd think it'd be easy," he says of commercializing an efficient process. "But we have not had the investment. We have not had the push. We have not had, quite frankly, the national need or thrust that the corn ethanol industry has."

The DOE has awarded some funding to lignocellulosic biorefineries. Under the Biomass Research and Development Initiative, Genera recently received a $2.4 million grant to research and improve switchgrass varieties in cooperation with Ceres and DDCE, Tiller says. With the funding, Genera will compare Ceres's improved switchgrass varieties to traditional ones on a large scale, she says. In addition, Genera was awarded a $4.9 million DOE grant to optimize removal, transportation and storage of switchgrass, including the use of in-field chopping systems instead of baling.

Downing shares Tiller's belief that dedicated energy crops will play a large role in the switch from petroleum and fossil fuels. Oak Ridge National Laboratory's Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply, commonly called the Billion-Ton Study, found that an estimated 1.3 billion tons of biomass feedstock could be available countrywide including agricultural residues, forest resources, herbaceous energy crops and woody energy crops, under a number of assumptions, probably the most important being land use, Downing says. But what that study did not address is equally important: Where are those feedstocks available? What are they? What will it cost? Downing and about 50 fellow scientists are going back to the study and elaborating on it, making some important changes and delving a bit deeper. The results should be released in June. "We'll have to go under scrutiny and knife, but we are optimistic, based on what the secretary [of energy] and the president say we should be producing for fuels by 2022, that we're going to have a significant amount of feedstock to satisfy that," he says. The U.S. renewable fuels standard, established in the Energy Policy Act of 2005, is 36 billion gallons by 2022.

"Growing switchgrass and trees isn't inexpensive," Downing says. "Picking up corn stover is not cheap either. There are nonexistent markets for some of these things; there are always alternative markets that farmers will seek out to provide the highest revenue for their farm enterprises. They don't care what it's used for; they just want the highest price."

Near-Term Profitability

"On a macro level, one of the key elements missing in biofuel feedstocks is that most are not profitable today," says Kirk Haney, president and CEO of California-based SG Biofuels. "Jatropha is." SG Biofuels has the largest library in the world of jatropha genetic material, along with 4-year-old field trials in Latin America. "Our business model is to develop jatropha so it's the highest-yielding with the lowest input costs," Haney says. "We think the most important thing is profitability for farmers."
In mid-January, SG Biofuels announced it had formed a strategic alliance with Life Technologies Corp., a provider of life science solutions, to further sequence the jatropha genomes and put the perennial plant on the fast track to commercialization. Life Technology's choice to partner with SG Biofuels signifies the promise and potential of the plant, Haney says. "It's really market validation for jatropha and market validation for our company," he says.

"The reality is, in the near-term, biofuels are going to play a very important strategic part in offsetting petroleum," he says, adding that jatropha will have a significant impact on that biofuels industry. Biodiesel from jatropha shows a 70 percent greenhouse gas reduction from petroleum biodiesel levels, he cites. "It's a fuel that works. It's profitable today, and with companies like ours, it's only going to get more profitable."

The plant has shown yields four to five times those of soybeans and two to three times the yield of rapeseed, Haney says. "Another reason we've approached jatropha is that Mother Nature has already developed this plant to a point where it's clearly a high yielder with lower input costs," he says, adding that it's well-known in the aviation industry. "It makes a great jet fuel," Haney says. "It's actually more fuel efficient than kerosene." The biomass portion of a recent 50-50 biomass/petroleum jet fuel blend consisted of 48 percent jatropha, 1 percent algae and 1 percent camelina.

SG Biofuels is working to identify favorable traits-including cold tolerance-that will allow the crop to be grown outside its native habitat of Central America. Jatropha can be grown on marginal or abandoned lands so as not to compete with food crops, and is not currently grown in the continental U.S. More than 800 million acres of nonagricultural land around the world could be used to plant jatropha, Haney says, and that does not include areas that could grow cold-tolerant strains. To put that in perspective, 50 million acres are planted with sugarcane today, and about 200 million each of corn and soybeans, he says.

SG, with its new partner, will continue to work with jatropha to bring it to market and has had success in its field trials and lab work. "We have some incredible data that will revolutionize the space," he says, adding that it's too early to disclose it. The alliance will develop region-specific cultivars, an aspect of energy crop production that both Haney and Downing believe is crucial. "One thing we think is missing with a lot of energy crops is not just doing trials in one specific area where the plant grows really well," Haney says, building on Downing's land-use viewpoints. "To get the plant to have the scale of a corn, a soybean, wheat and sugarcane, we have to grow it in different regions of the world." BIO

Lisa Gibson is a Biomass Magazine associate editor. Reach her at or (701) 738-4952.