Analysis of cost savings from networking pipelines in CCS infrastructure systems

The success of carbon capture and storage (CCS) in reducing CO ₂ emissions on a large scale will depend on effectively deploying CCS infrastructure. Key decisions will include where to build new capture-ready power plants or retrofit existing facilities, how to construct an integrated and robust CO ₂ pipeline network, and which geologic reservoirs offer the best and safest storage potential. Critically, the capture, transportation, and storage components are highly interdependent and must be considered simultaneously. In previous work, we have developed and applied a CCS system optimization model that simultaneously optimizes the investments in, and operation of, the source capture facilities, the pipeline network, and the geologic sinks. The simCCS model combines GIS and operations research techniques to optimize seven sets of decisions simultaneously: source capture investment; source capture amounts; pipeline network configuration; pipeline diameters; routing of CO ₂ amounts through the pipeline; sink injection investment; and sink injection amounts. In choosing the corridors for the pipelines, the model considers geographic factors such as steep topography, protected lands, urban areas, and rivers and roads. SimCCS develops a fully integrated and networked CO ₂ pipeline network in which pipelines can merge and branch to create trunk lines that reduce the overall network length and take advantage of cost savings through economies of scale and high capacity utilization. In this paper, we demonstrate the cost savings of using a model like simCCS to optimize simultaneously the seven key CCS decisions. Using a case study of the Midwest USA consisting of eight coal-fired power plants and seven depleted oil fields as potential sources and sinks, we use simCCS to optimize a networked CCS infrastructure system with trunk and feeder pipelines. We then compare those results to constrained runs of simCCS in which the pipeline branching capability is restricted to allow only direct pipelines between single sources and single sinks. For small amounts of CO ₂ captured, the optimal networks are the same, but as soon as the system requires more than one source and sink, the advantages of networking the pipelines begin to emerge. For systems involving more than one source and sink, total costs average 6.5% lower for networked systems than for direct systems, based on savings of 2% on source costs, 34% on transport costs, and 22% on sink costs. The source and sink savings are generated in the model by connecting the less expensive sources and sinks to the pipeline network. The total length of pipelines for the networked system is on average 43% lower, and pipeline capacity utilization is 12% higher. This analysis helps to demonstrate why comprehensive infrastructure modeling is important to the financial success of CCS.