Environment, Development and Sustainability, published online 11 July 2010

David J. Murphy, Charles A. S. Hall, and Bobby Powers

“Research on corn ethanol is overly focused on whether corn ethanol is a net energy yielder and, consequently, has missed some other fundamental issues, including (1) whether there is significant error associated with current estimates of the EROI of corn ethanol, (2) whether there is significant spatial variability in the EROI of corn ethanol production, (3) whether yield increases will translate linearly to increases in EROI, (4) the extent to which assumptions about co-product credits impact the EROI of corn ethanol, and (5) how much of the ethanol production from biorefineries is net energy. We address all of these concerns in this research by: (1) performing a meta-error analysis of the calculation of EROI, (2) calculating the EROI for 1,287 counties across the United States, and (3) performing a sensitivity analysis for the values of both yield and co-products within the calculation of EROI. Our results show that the average EROI calculated from the meta-error analysis was 1.07 ± 0.2, meaning that we are unable to assert whether the EROI of corn ethanol is greater than one. The average EROI calculated across 1,287 counties in our spatial analysis was 1.01, indicating that the literature tended to use optimal values for energy inputs and outputs compared to the average conditions across the Unites States. Increases in yield had a trivial impact on EROI, while co-product credits had a large impact on EROI. Based on our results from the spatial analysis and the location of biorefineries across the United States, we conclude that the net energy supplied to society by ethanol is only 0.8% of that supplied from gasoline. Recent work indicates that only energy sources extracted at EROIs of 3:1 or greater have the requisite net energy to sustain the infrastructure of the transportation system of the United States. In light of this work, we conclude that production of corn ethanol within the United States is unsustainable and requires energy subsidies from the larger oil economy.”

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Journal of Environmental Management, Volume 91, June 2010

Fritz Hellmann and Peter H Verburg

“This paper presents an assessment of the potential impact of the EUs biofuel directive on European land use and biodiversity. In a spatially explicit analysis, it is determined which ecologically valuable land use types are likely to be directly replaced by biofuel crops. In addition, it is determined which land use types may be indirectly replaced by biofuel crops through competition over land between biofuel and food crops. Four scenarios of land use change are analyzed for the period 2000-2030 while for each scenario two policy variants are analyzed respectively with and without implementation of the biofuel directive. The results indicate that the area of semi natural vegetation, forest and High Nature Value farmland directly replaced by biofuel crops is small in all scenarios and differs little between policy variants. The direct effects of the directive on European land use and biodiversity therefore are relatively minor. The indirect effects of the directive on European land use and biodiversity are much larger than its direct effects. The area semi natural vegetation is found to be 3-8% smaller in policy variants with the directive as compared to policy variants without the directive. In contrast, little difference is found between the policy variants with respect to the forest area. The results of this study show that the expected indirect effects of the directive on biodiversity are much greater than its direct effects. This suggests that indirect effects need to be taken explicitly into account in assessing the environmental effects of biofuel crop cultivation and designing sustainable pathways for implementing biofuel policies.”

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Center for Global Development, Working Paper 219

Kevin Ummel

“Coal power generation in China and India could double and triple, respectively, over the next 20 years, which would increase exposure to fuel price volatility, exacerbate local air pollution, and hasten global climate change. Moving to concentrating solar power (CSP), a growing source of utility-scale, pollution-free electricity, would help alleviate these problems, but its potential in Asia remains largely unexamined. In this working paper, Kevin Ummel uses high-resolution spatial data to identify areas suitable for CSP and estimates power generation and cost under various land-use scenarios.

“Total CSP potential in China is at least 16 times greater than current coal power output; in India, it is at least 3 times greater. A CSP expansion program could provide 20 percent of electricity in both countries by midcentury. Under conservative assumptions, the program will require subsidies of $340 billion in present dollars. Estimated costs are especially sensitive to the assumed rate of technological learning, making it especially important to form committed public policy and financing to reduce investment risk, encourage the expansion of manufacturing capacity, and achieve long-term cost reductions.”

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ASA, CSSA, and SSSA International Annual Meetings
31 October – 03 November 2010
Long Beach, California USA

David Archer

“The EPIC simulation model is used with SSURGO soils, field location information, and a transportation cost model to analyze potential biomass supply for a West Central MN bioenergy plant. The simulation shows the relationship between biomass price, locations of where biomass production is profitable, and impacts on economic optimum cropping practices. Results show expansion of production away from the bioenergy plant as biomass price increases. Also, increasing biomass price tends to increase harvest intensity and change the optimum crop rotation near the bioenergy plant. These changes have important implications for the environmental impacts of biomass harvest, since changes in harvest intensity and crop rotation can have substantial effects of soil erosion, soil carbon, and nutrient and pesticide runoff and leaching.”

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