Biofuel technologies and global decarbonization by 2050: the role of technological learning, spillovers effects and feedstock constraints

By 2023, bioenergy represented an important energy resource, accounting for approximately 10.81 % of global final energy consumption, or about 42 EJ/y. Of this value, around 35 EJ/y came from modern bioenergy, primarily modern solid biomass, while liquid biofuels contributed only 3.8 EJ/y. To support their net zero ambitions by 2050, several governments have set targets to increase the production of advanced biofuels, which utilize non-agricultural feedstocks, hence mitigating the environmental impacts of conventional biofuels. However, the deployment of these technologies faces several challenges due to high production costs and limited feedstock availability, creating uncertainty around the viability of these targets. This research develops a global integrated assessment model that incorporates learning curves and technological spillover effects for biofuel technologies calibrated using patent data. The model evaluates mid-century biofuel production across three scenarios, each varying in land resource availability and feedstock constraints, to provide insights about the effects of climate policy induced technological change. The scenarios are defined based on current literature exploring crop yields, land availability and food security, as well as residual feedstocks for advanced biofuels. Results show that climate induced damages can reduce conventional biofuels output almost by 6.004 EJ throughout the entire simulation period. Alternatively, it is found that across all scenarios advanced biofuels production remains below the technical potential found in most literature, and that when spillover effects are accounted for, a reduction of 7.13–13.7 % in the costs of advanced biofuels energy supply is achieved by 2050 across all scenarios.