Assessment of long- and short-term impacts of PtX on the German energy system – A combined TIMES and PyPSA modelling approach

Green hydrogen is central to decarbonising Germany's energy system, though its long-term role and system implications remain uncertain. Strategic models determine long-term expansion, but often lack spatio-temporal resolution to characterise operational implications. This study addresses this gap by soft-linking the TIMES-based TAM-Supply model with the high resolution PyPSA-Eur model, transferring capacity pathways into hourly, spatially resolved dispatch to quantify flexibility requirements. TAM-Supply indicates that by 2045, around 11 GW of domestic electrolyser capacity produces 90 TWh of hydrogen, complemented by 100 TWh of imports, with derivatives reaching 320 TWh, predominantly imported as e-methanol and e-fuel. The high-resolution analysis shows electrolytic hydrogen production and derivative imports concentrated in northern Germany, shaping transmission development toward central demand regions, alongside pronounced winter supply deficits requiring higher imports to offset reduced renewable availability. These findings show how high-resolution operational translation reveals flexibility requirements that long-term planning alone does not capture, for the reference pathway considered.