Switchgrass – America’s own biofuel. But is it any good?
In previous pieces we’ve looked at biofuels in general and at some different examples like the plainly lousy palm oil or the more promising and proven sugar cane. Less is known about others such as jatropha and green algae, but it is clear that all have their potential advantages as well as disadvantages, some already demonstrated.
Let us now examine switchgrass, a plant native to North America, which was widespread before European-style farming transformed much of the landscape where it once grew unheeded.
Switchgrass is a perennial, which means it doesn’t need annual replanting or reseeding. It is a hardy, diverse and adaptive grass and can grow in various climatic conditions as well as in soils considered too erodible, sandy or gravelly for other crops, including food sources like corn. This makes it less susceptible to both droughts and floods and hopefully not a potential factor in food prices. Neither does the cultivation of switchgrass require heavy nitrogen fertilization or herbicides. Besides biofuel, switchgrass can be used as a feedstock for biomass energy production and biodegradable plastics, as well as to prevent erosion and aid in soil conservation.
As a source of bioenergy, switchgrass can be used to make ethanol fuels, biogas and as a direct source of thermal energy. It is considered to be a moderate to high yield energy crop. Switchgrass also requires less energy input and has a favorable energy balance when compared to annual crops such as corn, soy and canola, while the price of production is estimated to be about half that of corn. Furthermore, switchgrass produces cellulosic ethanol, which is less polluting than the kind of ethanol made from corn.
Switchgrass has not received the same kind of publicity or enthusiasm as other biofuels such as corn and soy, and therefore has not achieved aspired levels of commercialization. In other words, it has not been successfully marketed. This is probably due to it being a new crop without the massive lobbies and already existing infrastructures belonging to other biofuel sources that are already established as food crops.
Despite the potential for switchgrass as an ethanol biofuel and its apparent superiority as one in some respects, it has not made much progress in that market. Where switchgrass seems to be making headway is as a heating fuel in private homes as well as commercial boilers and as a power source to replace or at least reduce the use of coal. This application of using switchgrass in pellet form as a solid biofuel shows promising energy ratios and potential for greenhouse gas mitigation. This CNN Business Wire report from September 30th and this New York Times blog from October 1st of this year discuss recent developments in this sector. Hopefully switchgrass cultivation will continue to make inroads where viable, but will not be pursued in ways that might affect food prices or have other negative environmental consequences, as has been the case with corn, soy and palm.
By Graham Land