As many as four ethanol plants are scheduled to begin operation in Texas this year and more than 15 biodiesel facilities are already running. Interest is high in renewable energy production, but farmers and the Texas ag industry should consider long-term effects on water and other grain-dependent industry needs as they develop strategies to help meet the nation's energy demand.

Ethanol

According to the Texas State Energy Conservation Office, ethanol production plants at Levelland, Hereford (2), and Plainview are scheduled to begin operation in 2008. Also start-up dates are to be announced for plants in Sherman County, near Muleshoe, and at Dumas. Other plants have been proposed for Dimmit, Sunray and Friona.

“By the end of 2008, the total annual ethanol production capacity for the High Plains is expected to be about 380 million gallons. About 128 million bushels of corn or grain sorghum will be required to produce this amount of ethanol,” said Calvin Trostle, associate professor and Texas AgriLife Extension Service agronomist, Lubbock.

In contrast, last year's grain production in the Texas High Plains totaled 177 million bushels of corn and 55 million bushels of grain sorghum, much of which was used in cattle feeding operations.

As a rule of thumb, for each 1 million gallons of annual ethanol production capacity the plant requires about 1,000 bushels of grain per day.

“What if we have to procure half of the needed grain in the High Plains to feed these ethanol plants at full capacity?” Trostle asks. “If we split evenly between corn and grain sorghum, and use 2007 average yields (around 200 bushels per acre for corn, 65 bushels per acre for sorghum), we'd need 160,000 acres of corn and 500,000 acres of grain sorghum.

“Price, supply and demand will probably determine how much locally-produced grain is used for ethanol production, and how much is freighted in from other areas.”

Depending on the efficiency of the production process and on how much water is recycled, it takes 4.0 to 5.5 gallons of water, “gray” or “fresh,” (At least two of the plants have made arrangements to use municipal waste water.) to make one gallon of ethanol. “This translates to about 55,000 to 77,000 acre-inches of water to manufacture 380 million gallons of ethanol. An acre inch is about 27,160 gallons,” Trostle said.

“To grow just half of the corn and grain sorghum to make 380 million gallons of ethanol as noted above, will require more than 8 million acre-inches of water, of which the majority will be for irrigation in the Texas High Plains.”

Under normal conditions corn can yield a little more grain per unit of water than grain sorghum. But sorghum can begin grain production with a lower initial amount of water. “This may make sorghum a little more desirable for grain-based ethanol production where water is limited,” Trostle said.

“Ethanol can also be produced from wheat straw, corn and grain sorghum stalks, cotton gin trash, rangeland grasses, forage sorghum, sweet sorghum, switchgrass, or even mesquite,” Trostle said. “And using these feedstock sources in a ligno-cellulose conversion process can be more efficient in producing ethanol than using grains. However, this process requires a much greater capital investment and takes significantly more time to ferment a given amount of ethanol.”

Biodiesel

There are currently more than 15 biodiesel plants in Texas with an annual capacity of 120 million gallons of biodiesel.

Brownfield Biodiesel at Ralls, Texas, with a capacity of 2 million gallons per year, uses canola oil from Denver, Colorado, as the primary source of feedstock. Initially, cottonseed oil was used as the feedstock, but it became too expensive.

Southwest Energy and Feed Company is planning to open a biodiesel plant near Seminole in April 2008. It will have a capacity of 1.6 million gallons per year. The planned feedstock will be cottonseed from the local area.

“Oil from many oilseed crops can be used to make biodiesel. Among these are cotton, peanut, soybean, sunflower, canola, and safflower. Most of these have the potential to produce modest oil yield under either dryland or minimal irrigation in West Texas,” Trostle said.

“Processing oilseeds for biodiesel is much less complicated than producing ethanol. The oil produced from various crops, however, is routinely more valuable for use in foods and commercial/industrial products than it is for use in producing biodiesel.

“For example, runner peanuts at three tons per acre in Gaines County would currently net at least $350 per acre more (gross about $1,500 per acre) at the 2008 contract price than what a biodiesel refiner could afford to pay for the oil to make biodiesel priced at $3.50 per gallon,” Trostle said.

Considerations

Trostle poses questions he believes should be considered when discussing the possible future of bioenergy production on the High Plains and the impact on groundwater resources.

“First, and quite simply, what is the value of water? Is it more valuable for home and business use (a small fraction of total water use in West Texas); industry and manufacturing; growing crops for oil, food, fiber, and feed for dairy and beef animals? How will that value compare to its value for ethanol and other bioenergy production?

“The drive behind developing homeland bioenergy resources has been to reduce dependence on foreign oil and create energy from renewable resources. Ethanol surely has a role to play. However, for West Texas, if that ethanol, or any other energy resource, is dependent on what is essentially ‘non-renewable’ Ogallala water, then is the energy truly renewable?

“How West Texas addresses these and other questions will determine what kind of future we have in the High Plains and the sustainability of our fledgling bioenergy industries.

“For further industry information about ethanol and biodiesel consult http://www.ethanol.org and http://www.biodiesel.org.”