These are two cost abatement schemes used in the CCUS Hub Search. The base case assessment assumes every relevant emitter in the cluster deploys CCUS. While this minimizes the overall transport & storage cost, it overestimates the CCUS deployment potential. The preferred scale assessment defines clusters that represent the best trade-off between achieving a minimum scale (2Mt CO2) and deploying CCUS on assets for which it is a lower cost abatement lever.
In reality, CCUS deployment depends on more than just costs, so these schemes should be used to assess the relative cost potential of different regions and to compare CCUS costs vs. other abatement options.
A carbon capture, utilization and storage hub typically has a dense group of emitters sharing infrastructure to lower the cost of transporting and storing captured CO2 or using it in industrial applications. Beyond the physical presence of all the elements of the chain, a hub tends to benefit from greater policy and regulatory support, positive stakeholder attitudes and commercial foundations that facilitate risk sharing between participants.
This is an estimate of the amount of CO2 that can be stored deep underground in the pore spaces of rocks where they remain trapped for tens of thousands of years. The most common storage resources are depleted oil and gas reservoirs or saline aquifers (marked in our map as blue and green hexagons, respectively). CO2 can also be stored in working reservoirs, a process known as enhanced oil recovery (EOR). While this can help hub economics in the early stages, the CCUS Hub search does not include these stores since they will not be sufficient for large-scale hub storage over time. There is also increasing activity exploring the possibility of storing CO2 in basalt. formations. The methods for determining how much CO2 can be stored depend on the type of rock.
These represent bands of average abatement costs expected in the hubs evaluated. This is a weighted average of the costs of capturing, transporting, and storing the CO2 for all the emitters in a cluster. The transport and storage infrastructure is assumed to be shared.
These are underground rock formations that have been emptied of the original oil or gas content over years of production. These are considered as some of the cheaper locations to store CO2 permanently as they are usually geologically well known and may also have existing infrastructure, such as pipelines that may be repurposed for CO2 transport. These tend to be relatively limited in the cumulative volume of CO2 they can hold. There are also some risks associated with re-using the existing infrastructure, such as old sealed wells in the reservoirs that may serve as a point of leakage over time if not managed carefully.
Bountiful underground rock formations that currently hold salty water. These are widespread (in some cases co-located with depleted oil and gas reservoirs), can hold huge volumes and don’t have issues around existing infrastructure. That makes them a very attractive long term store, even if they are a bit more expensive to develop. In fact, many of the developing CCUS hubs, such as Northern Lights and Net Zero Teesside, have targeted saline aquifer storage.