Reducing Economy-Wide Greenhouse Gas Emissions with Electrofuels and Biofuels as the Grid Decarbonizes

Biofuels and electrofuels have the potential to complement electrification in speeding greenhouse gas emissions reductions, especially in hard-to-decarbonize sectors. Concentrated waste CO2 streams that can be used as a feedstock for electrofuels, however, may become less available as the share of renewable electricity increases and industries undergo decarbonization. We conduct an analysis with detailed treatment of biofuels and electrofuels to probe their role in decarbonizing multiple industrial sectors and transportation. We examine how the changing availability of CO2 could affect electrofuel production and the potential role of direct air capture in stabilizing the supply of CO2. The results indicate that biofuels could fulfill 12% of the total final energy demand across all U.S. sectors in 2050. Using seven industrial source points of CO2 available in 2050, 15,388 PJ of electrofuels could be produced, which amounts to 25% of the total final energy demand. This result holds even upon decarbonization that requires direct air capture to boost the CO2 supply. Biofuels and e-fuels have the potential to reduce economy-wide GHG emissions by 7 and 21% beyond electrification alone. However, electricity consumption and land use grow markedly with decarbonization at scale.