Biofuel Organisms - Switchgrass

Switchgrass (Panicum virgatum) is a perennial grass that grows natively in Canada and the United States. It is one of the dominant species of plant in the American prairie. Initially used only for erosion control and ornamentation, the grass has recently found use as a biofuel and for the production of biodegradable plastics.

Biofuel Properties

Switchgrass is considered a moderate to high yield plant, which means it isn’t as prolific as Jatropha, but provides better growth in the North America than corn or soybean. What makes switchgrass really interesting is that it can be used to make ethanol, but it can also be burned directly for thermal applications, such as the production of electricity. The lack of conversion steps makes switchgrass easy to use and relatively efficient in terms of energy input versus energy obtained from it.

The energy investment into switchgrass is about three and a half times less than the energy investment for grain or corn. Further, an investment of up to 1.34 gigajoules of energy into switchgrass yields up to 2.66 gigajoules in return. So, switchgrass is a net energy producer unlike many biofuel feedstocks. Cost compared to corn is about 50%, make switchgrass more attractive for ethanol production as well.

Land Use

In the United States, corn is heavily subsidized by the federal government and so more corn is planted than is put into the food supply. That excess land could be used to grow switchgrass. Additionally, switchgrass is about 3 times more efficient than corn. If the aviation fuel comparison is used, then switch grass would require somewhere on the order of 3 million square kilometers, which is more than Camelina or Jatropha.