Policies supporting biofuels, which are mainly used in transportation, were thus blamed for spikes in food prices in 2007 and 2008 (OECD, 2015). Growing food crops for conversion into a biofuel (e.g. ethanol) in a refinery (for subsequent combustion in a power plant) will have different land-use impacts from growing woody crops for direct combustion. In addition, the efficiency of bioelectricity processes vary: while woody crops yield more biomass per unit area than a food crop like corn or soybean, biofuel-related processes like ethanol combustion usually convert a higher percentage of biomass energy content into electricity (Fthenakis and Kim, 2009).