Jason Hill, research associate in the departments of Applied Economics and Ecology, Evolution and Behavior at the University of Minnesota, drew a standing-room-only crowd to the St. Olaf campus Thursday night. His lecture, entitled “Biofuels Basics: Energetics, Expectations, Environment and Economics,” outlined and expanded on the findings of research recently published in Science magazine.
Hill and U of M ecologist David Tilman have received international attention for this work, which indicates that low-input high-diversity (LIHD) mixed perennial grasslands, essentially native prairie, offers tremendous promise for sustainable production of biofuels on degraded agricultural land in a way that actually sequesters atmospheric carbon dioxide.
This and previous research by Hill and Tilman indicates that even use of 100% of the US corn harvest for ethanol production would offset only about 2.4% of current US gasoline use when accounting for all energy inputs. Similarly, using 100% of the US soybean harvest for biodiesel production would offset only about 3.1% of US diesel use. Clearly, corn-based ethanol and soybean-based biodiesel on their own will not significantly affect US dependence on foreign oil (or fossil fuels in general). Even at the current rate of corn use for ethanol production (about 17% of the US crop), there are indications of unintended consequences of the food/fuel competition. While high and rising corn prices are good in the short run for US corn growers, the cost of tortillas in Mexico (where tortillas are a dietary staple) have gone through the roof recently, and some analysts are pointing to ethanol as one of the factors contributing to this problem. In addition, there are significant environmental consequences (soil erosion, water quantity/quality issues, etc.) of intensive corn and soybean production.
Their LIHD grassland approach, on the other hand, offers tremendous promise. Hill summarized the key benefits of LIHD grassland biomass production:
- It is producible on degraded lands
- Provides a highly sustainable and stable fuel supply
- Cleaner rivers and groundwater
- More net energy gain per acre than food based
- Can be used to power existing biofuel processing facilities.
Hill’s research indicates great promise for LIHD biomass production and generation of electricity and synfuels (e.g. gasoline and diesel fuel produced from biomass) produced in local “biorefineries.”
The crowd of 125 engaged Hill in a lively Q and A session after his lecture. While the proposed Bridgewater township corn ethanol plant remains highly controversial locally, it’s clear that there is interest in seriously exploring next-generation biomass-based energy production.