Multi-sectoral impacts of H ₂ and synthetic fuels adoption for heavy-duty transportation decarbonization

Abstract We assess the bulk energy system impact of decarbonizing heavy duty vehicle (HDV) based road transportation via the use of either hydrogen (H 2 ), or drop-in synthetic liquid fuels produced from H 2 and CO 2 . Our analysis soft-links two modeling approaches: a) a bottom-up model of transportation energy demand that produces variety of final energy demand scenarios for the same service demand and b) a multi-sectoral capacity expansion model that co-optimizes power, H 2 and CO 2 supply chains subjected to technological and policy constraints to meet exogenous final energy demands. Through a case study of Western European countries under deep decarbonization constraints in 2040, we quantify the energy system implications of different levels of H 2 and synthetic fuels adoption in the HDV sector under scenarios with and without CO 2 sequestration. In the absence of CO 2 sequestration, substitution of liquid fossil fuels in HDVs is essential to meet the deep decarbonization constraint across the modeled power, H 2 and transport sectors. Additionally, utilizing H 2 HDVs reduces total modeled system costs and liquid fuel demand relative to synthetic fuel–based pathways. Synthetic fuel adoption generally increases DAC deployment and associated system costs. The study highlights the trade-offs associated with different transportation decarbonization pathways, and underscores the importance of multi-sectoral considerations in decarbonization studies.