LIFE-CYCLE GREENHOUSE GAS EMISSIONS OF BIOMETHANE AND HYDROGEN PATHWAYS IN THE EUROPEAN UNION

Abstract

This study aims to support European policymakers with a better understanding of the uncertainties regarding gaseous fuels’ roles in meeting climate goals. Life-cycle GHG analysis is complex, and differences in methodology as well as data inputs and assumptions can spell the difference between a renewable gas pathway qualifying or not for REDII eligibility at the 50% to 80% GHG reduction level. It is thus important for European policymakers to use robust LCA to ensure that policy only supports gas pathways consistent with a vision of deep decarbonization. For this purpose, we conduct sensitivity analysis of the life-cycle GHG emissions of a number of low-GHG gas pathways, including biomethane produced from four feedstocks: wastewater sludge, manure, landfill gas (LFG), and silage maize; and hydrogen produced from eight sources: natural gas combined with carbon capture and storage (CCS), coal with CCS, biomass gasification, renewable electricity, 2030 EU grid electricity, wastewater sludge biomethane, manure biomethane, and LFG biomethane. For each pathway, we estimate the life-cycle GHG intensity using a default central case, identify key parameters that strongly affect the fuel’s GHG intensity, and conduct a sensitivity analysis by changing these key parameters according to the range of possible values collected from the literature