Home grown or imported? Biofuels life cycle GHG emissions in electricity generation and transportation

Few previous studies consider the GHG implications of biofuels in electricity generation. Yet, the biofuels have become a key replacement for residual petroleum fuel and LNG in stationary power in Hawai‘i. This stems from isolated island grid and heavy dependence on imported oil, characteristics which are shared with many island regions. This study calculates life cycle GHG emissions from biodiesel and renewable fuel oil from soybean, oil palm, and jatropha in electricity production as well as the transportation sector. By using Hawai‘i as a case, this study aims to compare biofuels supply chain systems for imported and locally produced. The results indicate that variations in GHG emissions reduction are dictated by the choice of feedstock crops and byproduct credits rather than the distance between the fuel production and end-use location. The study suggests that locally produced biofuels have lower GHG emissions than imported ones but the difference is trivial. This study does not calculate the monetary cost of switching to biofuels; instead, it uses GHG emissions as a unit of measurement to show the trade-offs among different counterfactual scenarios in fuel production location, feedstock crops, and supply chain pathways.