Global techno-economic potential of Power-to-X technologies for sustainable fuels, chemicals, and food supply

Abstract

Global warming must be limited to 1.5°C above pre-industrial levels to reduce the risks and impacts of climate change. Achieving this goal requires net-zero anthropogenic CO2 emissions and a decline in other greenhouse gases by mid-century. Greenhouse gas emissions could be greatly reduced by transitioning to a sustainable, highly electrified energy system and a mostly vegetarian diet. However, direct electrification is not a viable solution for some emissions, such as fuel emissions in long-range marine and aviation transport or non-energy emissions from agriculture, cement production, and fossil feedstock in industry. To address these hard-to-abate emissions, alternative solutions are explored, such as bio-based fuels and materials, electricity-based (e-)fuels and chemicals, and alternative foods, as well as carbon capture and utilisation or sequestration methods.

This dissertation aims to assess the techno-economic viability of power-to-X technologies for indirect electrification of hard-to-abate sectors by production of hydrogen, ammonia, and methanol (as transportation fuels and feedstocks for industry), and microbial protein (as a food building block) from water and atmospheric carbon dioxide and nitrogen using renewable electricity. Accordingly, islanded hybrid solar photovoltaics-wind power-to-X systems coupled with balancing technologies are modelled to determine cost-optimized system configurations and production cost-volume globally, based on hourly solar and wind data in 0.45º×0.45º spatial resolution from 2020 to 2050 in 10-year increments.

The results indicate that access to low-cost electricity and flexible operation are essential for producing affordable e-products. Solar photovoltaics are projected to dominate electricity supply in most regions, providing abundant power for global power-to-X demands. As CO2 direct air capture matures, its cost is projected to decline sharply, and heat integration in power-to-X systems further reduces its energy cost. e-Products with moderate transportation costs can be imported from least-cost global sites. Economically, e-protein is the most viable option, followed by e-ammonia. Moderate CO2 emissions costs are essential to make e-fuels and e-chemicals cost-competitive with fossil-based counterparts. Nevertheless, e-products are expected to reach the current market prices of the fossil counterparts in the coming decades, enabling significant reductions in hard-toabate emissions at no additional cost by mid-century.