Exploring Initial CO2 Transport Topologies for Germany's Carbon Management

Abstract

Germany's climate target requires carbon capture and sequestration for residual emissions from hard-to-abate sectors such as cement production and waste incineration. Planning this infrastructure is challenging because capture investments and CO2 transport networks are strongly interdependent. Existing energy system models capture system-wide interactions but provide limited insight into robust transport topologies, while detailed infrastructure studies usually neglect feedbacks with the wider energy system. This study combines graph-theoretic topology generation with a large-scale sector-coupled energy system model to evaluate alternative CO2 transport networks for Germany in 2035. We generate and evaluate 60 candidate topologies that differ in network length, sink accessibility and source prioritization. The deployment of a domestic CO2 transport network reduces German consumer costs by around 22 bnEUR/a relative to a scenario without CO2 pipelines. The resulting network is primarily used by industrial point sources, including process emissions, cement production and biomass-based carbon dioxide removal, while contributions from backup power generation remain comparatively small. Transport corridors are repeatedly selected and utilized in north-western Germany, reflecting the concentration of industrial CO2 sources and access to international sequestration routes. Early access to Dutch sink infrastructure provides particularly high system value. Compared to 1500 km, as little as 500 km of CO2 pipeline infrastructure captures most of the economic benefit when North Rhine-Westphalia is connected to the Netherlands, while also limiting long-term transport infrastructure lock-in. These findings suggest that the availability of CO2 transport infrastructure is more important than the exact topology once major industrial source regions and sink access points are connected.