CO2 storage capacity in Depleted Gas Fields, the Netherlands Subtitle: Portfolio Study

TNO-Advisory Group (TNO-AGE) prepared this report for the Dutch Ministry of Climate Policy and Green Growth (KGG). The dual aim of this report is to support policy and decision makers in the emerging CO2 storage industry and to address the EU reporting obligations under the Net Zero Industry Act (NZIA). It provides an initial assessment of the offshore underground CO2 storage capacity in (nearly) depleted gas fields in the Netherlands, which is estimated at a ~1260 to ~1750 Mt (Mega tons) range for practical storage capacity in 46 and 124 storage sites respectively. It includes an examination of the potential development of available storage capacity through time at portfolio level, which is compared to the currently planned transport capacity development. In this report we (TNO-AGE) estimate the potential storage capacity in offshore depleted gas fields in the Netherlands following the resource "pyramid methodology". Theoretical capacity corresponds to the maximum physical storage capacity for CO2 in depleted gas fields, which for the offshore Netherlands we estimate at ~2860 Mt. Effective capacity incorporates additional geotechnical and engineering restrictions. This leads to a reduction of the available storage capacity down to ~2570 Mt. Further analyses are recommended that are likely to have a negative impact on this volume. For practical capacity, economic and legislative criteria are included that can have a significant impact but are not yet fully clear. In this report we consider impactful economic and legislative parameters to generate a high- and a low-case scenario, which together provide a first order uncertainty range of ~1260 to ~1750 Mt, in 46 and 124 storage sites respectively. Most of the practical storage is located in a limited number of medium to large size storage sites. This practical capacity range can be used for policy and stakeholder decisions as capacity range that can be realistically achieved.