The role of low carbon fuels towards net-zero in integrated assessment models and energy system models: A critical review

Low-carbon fuels (LCFs) such as green hydrogen, synthetic hydrocarbons, and biofuels are critical for decarbonizing sectors that are difficult to electrify. In this study, we present a globally harmonized techno-economic assessment of 21 LCF production pathways, including power-to-X, biomass- and sun-to-liquids, and multiple hydrogen routes, evaluated across all countries under three future scenarios for 2024, 2030, and 2050. The model integrates spatially explicit resource data, learning-driven capital cost trajectories, and dynamic, country- and technology-specific costs of capital, supported by robust scenarios and uncertainty analysis. By 2050, median levelized costs are projected to range from 0.07 to 0.10 EUR2024 per kWh for green hydrogen, 0.15 to 0.18 EUR2024 per kWh for power-to-liquid kerosene, and 0.14 to 0.20 EUR2024 per kWh for most bio-based aviation fuels, reflecting both substantial progress and persistent regional disparities. Our results show that while innovation, technology learning, and deep power sector decarbonization can unlock cost-competitive electrofuels in countries with abundant renewables, bio-based routes are frequently cost competitive for sustainable aviation fuel (SAF) production in near-term scenarios, and solar-to-liquid fuels remain constrained by feedstock availability and capital barriers. Nuclear- and methane-based hydrogen emerge as primary options in many regions, as well as the dominance of turquoise hydrogen in Russia, the Middle East, and Central Asia where carbon management is viable, which highlights the context-specific nature of future LCF systems. We also found that the least-cost logistics for global hydrogen trade will shift from ammonia shipping to pipeline transport and methanol delivery, with North Africa and Iberia emerging as leading suppliers to Europe. These findings underscore the need for integrated innovation, policy coordination, and investment strategies that address both resource and financial barriers, in order to achieve scalable, resilient, and cost-effective LCF supply chains worldwide.

An important step for moving forward in developing a sustainable fuel production: The SWEET Consortium reFuel.ch and the Port of Sohar and Freezone in Oman are joining forces for launching a research and production facility. Their commitment to collaborate in upscaling sustainable fuel production is marked by a letter of intent, signed at the Green Hydrogen Summit in Oman in December 2025.

The fourth virtual Round Table of the SWEET Consortium reFuel.ch, held on November 19, brought together 76 participants from industry, public administration, and academia. Taking place twice a year, the event fosters knowledge exchange on technology and policy readiness and tracks developments in the emerging market for renewable and low-carbon fuels.