There is a strong ambition to accelerate the deployment of Carbon, Capture, Utilization, and Storage (CCUS) throughout Europe, as a part of the European Green Deal (European Commission, 2019), the European Climate Law and to increase climate energy and climate targets for 2030 (Tumara et al., 2024). As part of this, the EU funded network project CCUS ZEN has connected CCUS actors in Europe, to identify promising value chains and to share knowledge and experience. We carried out a high-level technical mapping focused on emission sources, storage sites, transport infrastructure, utilization options and renewables, alongside non-technical mapping including stakeholder needs, regulations, climate policies and funding opportunities (Figure 1). These aspects should be considered when CCUS value chain are to be developed further after the initial technical high-level screening. One of the objectives was to explore the potential for CCUS value chain deployment in two regions with lower maturity level for CCUS compared to the current development in the North Sea region. A high-level screening of promising value chains has been carried out for two selected regions: the Baltic Sea region and the Mediterranean Sea region (Ringstad et al., 2023). The overall screening workflow was tested in the two geographical regions, with different geological storage sites (aquifers and depleted oil and gas fields) and led to the definition of 8 CCUS value chains, several with different transport solutions included, using ships or pipelines or a combination (Gravaud et al., 2024).

Several studies have been carried out focusing on high-level CCUS value chain screening with scenario developments (Jakobsen and Brunsvold, 2011), infrastructures (Kjärstad and Johnsson, 2009; European Commission, 2024) and storage sites (Anthonsen et al., 2014a; Anthonsen et al., 2014b). The high-level CCUS technical value chain can be subdivided into four main parts covering mapping of CO₂ emitters, infrastructure screening, storage sites screening and utilization as a final part in the puzzle (Lothe et al., 2025) (see Figure 2). For each part of the value chain, several key input parameters are listed without ranking the importance, costs, or effort to get enough data to draw solid conclusions.

As part of the high-level CCUS technical screening, an open geographical information system (QGIS) has been used for mapping the emitters and storage sites from previous reports, and to illustrate emission clusters and possible transport routes, both existing and future infrastructures. The aim is to carry out a first qualitative high-level screening, a more quantitative assessment of potential CCUS value chains are presented by Shogenova et al. (2025).

Figure 3 shows the results of the high-level screening of the Baltic and Mediterranean regions, highlighting marked emission sources and storage sites. The number of facilities and CO₂ emission sources varies significantly between countries, including significant emitters in both regions (Table 4). Large clusters of emitters are found in Poland and Germany in the Baltic region, as well as in Italy and Turkey in the Mediterranean Sea region. A comparison of the summarized numbers for the two regions reveals that the number of facilities and the annual CO₂ emissions are in the same range, with around 800 facilities and approximately 700 Mtpa (million tons per annum) in emissions. In the Baltic Sea region, large deep saline aquifers with significant storage capacities are mapped for Denmark, totalling 16,042 Mt (note that depleted hydrocarbon fields are excluded from this total), and for Poland, which has a storage capacity of 8,885 Mt, including both aquifers and hydrocarbon fields. In the southern region, Spain, Italy, and Greece demonstrate significant storage capacities, ranging from approximately 3.1–4.8 Gt, as illustrated in Table 5. Overall, the Baltic Sea region has three times more mapped storage capacities than the Mediterranean Sea region, with 33 Mt compared to 13.5 Mt, as shown in Table 5.

CCS projects and storage sites have been planned and evaluated in Italy for the past few decades; however, none have been carried out at full scale. The Brindisi CCS Project in southern Italy was evaluated by Enel and ENI using post-combustion technology, but the project was halted in 2016. The first CCS Hub in Italy, the Ravenna Carbon Capture and Storage (CCS) project, located in northeast Italy, started to inject in 2024, with Eni and Snam as operators (Figure 5). For phase 1, 25,000 tons of CO2 emitted from Eni’s natural gas treatment plant in Casalbosetti, Ravenna, are transported by pipeline and stored offshore Ravenna in a depleted gas field, with a potential impact of 10 Mtpa by 2030. Given that the Ravenna CCS project is ongoing in northern Italy, we will focus on mapping the potential CCUS value chain in southern Italy. In this article, we will further explore the Bradanica storage site onshore, southwest of Taranto (Figure 5).

The European Union and the United Kingdom are major energy consumers and CO₂ emitters, accounting for 12% of global emissions. The EU announced the Green Deal in 2019 to establish a roadmap for reducing emissions by at least 55% by 2030 and achieving zero emissions by 2050 (European Commission, 2019). Carbon capture and storage can be an important technology to contribute to fulfilling this ambition. In this article, we present a high-level CCUS value screening workflow and emphasize the main components needed in such a screening and workflow (Figure 2). The workflow has been tested in two regions in Europe that are less mature in terms of CCS: the Baltic and Mediterranean regions, with a more detailed case study presented for Italy-Greece. We will discuss several challenges in mapping a CCUS value chain, starting with the identification of emitters.

One of the results from the high-level CCUS screening in the two regions is that the number of emitters and the volume of emissions are in the same range for the Baltic and Mediterranean regions, with between 800–875 facilities and emissions approximately 700 Mtpa. For storage capacity, there are larger differences, with three times larger storage capacities mapped in the Baltic region compared to the Mediterranean region. One reason for this, is the easier access to data for the CCUS ZEN project in the Baltic region. More data has been made available in the Baltic over the last 3 decades. In the Mediterranean Sea, we did not have access to data for offshore France, we had little information from Italy and insufficient data available for the Castellon storage site in Spain, owned by the REPSOL oil company, which is currently planning detailed exploration for CO₂ storage in the TarraCO₂ project.

Reducing uncertainty in storage capacity, storage injectivity, and the longevity of a storage site is important. One major bottleneck at present is the lack of open geological datasets, including both 2D and 3D seismic datasets, and/or data from wells for potential storage formations. The underlying datasets needed, such as interpreted 2D seismic or 3D seismic data from existing wells, geological models, and/or reservoir models, are seldom publicly available. Scarce data coverage poses a major challenge in many regions, and in the CCUS ZEN project, the mapping of storage sites heavily relied on previous research projects. Since the screening of potential storage sites was based on publicly available data, it resulted in varying mapping coverage.

Another challenge related to mapping storage sites is the capacity of these potential storage locations. Indeed, databases present many sites with insufficient storage capacity for an operational CCS project to take place. For example, in Southern France, existing capacity data are on the order of a few tens of Mt, or even smaller, per site. Consequently, it is challenging to find sufficient storage capacity for the identified emission clusters and to build large-scale value chains. This is also a reason why transnational scenarios were developed. Finland lacks any storage potential, as it only has bedrock, and therefore the selected value chain suggested in CCUS ZEN involves pipeline or ship transport from Helsinki, Finland, to Rødby, a storage site in Denmark (Gravaud et al., 2024). Sweden has sedimentary deposits in the Baltic Sea, such as the Cambrian Faludden Formation, but with low storage potential, e.g., dipping aquifers with small natural closures (e.g., Lothe et al., 2016). However, the structures continue southwards on the Polish side and may serve as a potential storage structure.

For emission sources, there are complexities in deciding which industrial sites should be prioritized for CCS. The emission sources are subdivided based on the type of industry, varying from refineries, chemicals, power, hydrogen, energy from waste, cement, paper and pulp, iron and steel, and others. For some industries, CCS is the obvious option to reduce emissions (e.g., cement industry), while in other cases, CCS may be one of several options (with some form of electrification often being another). The level of CO₂ emissions in the future and the longevity of an industrial plant can also be factors in considering the deployment of CCS. However, information on this is difficult to obtain. It can be commercially sensitive, and there may also be political considerations that are hard to assess. For this reason, in this high-level screening, only the current emission levels from different industries are considered.

When choosing the emitter hub, several factors were evaluated. The type of industry, the number of emission sources, and, importantly, the location are very important factors. If there are several large industry clusters that can share common infrastructure, such as pipelines and/or buffer storage and/or ship transport, this can be crucial for building out an emission hub. In addition, the possibility of sharing a storage site would be beneficial for the emitters and for the owner of the storage site. The possible choice of storage sites are very much dependent on the transport infrastructure needed and the possible costs. In a high-level screening, only different options with distance in kilometres are shown.

For CO₂ emitters, a hub structure is attractive (Wang, 2024) to reduce the risk for each industry actor. A hub structure also minimizes the risk that transport, and storage infrastructure will be underutilized. A hub with more emitters will be less dependent on the emissions of a single industrial site for maintaining a high degree of utilization. In the screening, the total emissions amount of the clusters and the storage capacities are considered. However, it is recognized that actual total CO₂ emission volumes should be treated with caution. On one hand, the total amount of the clusters’ emissions does not exactly represent the amount of captured CO₂ but rather a maximum, as not 100% of the emissions would necessarily be captured. For some industries, transitioning to renewables or biogenic feedstocks may be more attractive and easier to implement.

In the example from Southern Italy, the high-level mapping for the entire CCUS value chain is essential to evaluate obstacles. Currently, Ravenna CCS has already started to inject CO₂ in their hub, and significant efforts are being made in Greece to clarify the offshore site Prinos for CO₂ storage (Koukouzas et al., 2009). However, as we see from the CO₂ emission hubs, there are potentially several emitter hubs in Southern Italy, where CO₂ can be transported via pipelines to the onshore Bradanica storage site. The storage capacity is around 344 Mt, assuming a storage efficiency of 1%, while using a storage efficiency of 4% results in around 1,276 Mt CO₂. Assuming an injection rate of 2 Mtpa in two wells, the storage site could be used for a minimum of 172 years. If we are less conservative, assuming a storage efficiency of 2%, the site could store for hundreds of years. Most likely, more injection wells could be an option, but to resolve this and de-risk the storage site, detailed reservoir modelling should be carried out. To develop a high-level value chain, all present and future stakeholders along the value chain need to be informed and aligned. Several key actors and driving forces will shape CCUS value chains, and these should be involved in the workflow. There is a strong interdependency among stakeholders with different interests, from industry emitters to transport and storage owners. To reduce risks, both economically and in terms of time spent, partnerships (or collaboration between stakeholders) across the value chain should be established.

Non-technical parameters influencing CCUS value chain developments include social, political, regulatory aspects, as well as economics, monitoring, reporting and verification and contracting. Communication with regulators, local public and non-governmental organisations and rising their awareness are always needed, but it is a time-consuming process (Honegger et al., 2024).

The export of CO₂ to offshore storage sites needs CO₂ storage regulations to be implemented internationally; (London Protocol (LP) 2009 Amendment to article 6, or/and its Provisional Application) and regionally (Helsinki Convention in the Baltic (HELCOM) and Barcelona Convention in the Mediterranean region), in addition to national regulations and permits needed for CO₂ storage both in onshore and offshore sites. At the present time LP 2009 Amendment to article 6 is implemented only in some studied countries of the Baltic Sea region (Denmark, Finland, Sweden and Estonia - among 13 countries implemented it in total). Denmark, Finland and Sweden are among nine countries in total which deposited declaration to allow for the Provisional Application of the 2009 amendment to article 6 of the LP. These regulations are not yet implemented in the Mediterranean Sea region, although there are some plans of Italy to do this including cooperation with France and Greece for bilateral agreements (IMO, 2025; Shogenova et al., 2024b).

The CO₂ storage is banned in the Baltic Sea now, according to the HELCOM, but The HELCOM recently decided to prepare in 2025–2026 the EIA (Environmental Impact Assessment) for CO₂ storage under the seabed in the Baltic Sea (information from personal communication of authors with national ministries). According to the initial Protocol of the Barcelona Convention CO₂ storage is permitted in the Mediterranean Sea. Public acceptance of CCUS technology in the studied regions is from low to medium with higher number of „medium” countries in the Baltics (Honegger et al., 2024).

The national regulations in the regions are developed in different directions. In the Baltic Sea Region, there are positive examples of Poland recently permitted CO₂ storage offshore and already prepared permitting regulations for onshore storage (to be published soon), and Latvia working in 2025 on CCS regulations towards its full implementation and possible permitting of CO₂ storage.

However, there is a negative example in the neighbouring Lithuania, which has banned any CO₂ injection since 2020, after CO₂ storage was initially permitted after full implementation of EU CCS Directive in 2011–2012 (Shogenova et al., 2013; Shogenova et al., 2021). These examples are clear signs of the increasing public awareness and acceptance of the technology in Poland and Latvia and low public acceptance in Lithuania. The Nordic countries are good examples of the positive influence of the non-technical issues, including policies and national financial support, on fast development of the CCUS technology, especially successful in Denmark with large numbers of very good storage sites and significant storage capacity.

The CCUS technical value chain screening involved mapping CO₂ emitters, infrastructure, storage sites, and utilization options using an open geographical information system. Emission sources were mapped to identify CO₂ capture sites, focusing on clusters for efficient transport to storage in the Baltic and Mediterranean regions. Data from the EU Emissions Trading System and the European Pollutant Release and Transfer Register were used for this mapping.

Existing and future CO₂ transport infrastructure was evaluated, including pipelines and shipping options, with a focus on combining methods for efficiency and compliance with regulations. Potential storage sites were categorized into saline aquifers and depleted reservoirs, with capacity estimates based on previous studies. The screening considered various geological data sources. CCU technologies were explored, utilizing CO₂ for producing chemicals and fuels, with data sourced from the CO₂ Value European database.

The screening revealed significant emitters in both regions, with around 800–875 facilities in each region emitting approximately 700 Mtpa. The Baltic region had larger mapped storage capacities than the Mediterranean. Eight CCUS value chains were developed based on emitter clusters and storage options, with a focus on transport scenarios.

The high-level CCUS value chain screening has been summarised in Figure 2, with mapping of emitters, transport infrastructure and storage sites, and utilization as a theme closely connected to capture screening. High-level CCUS value chain screening is the first step, evaluating the main tasks and research tasks that need to be addressed. The screening should serve as a tool to engage relevant stakeholders for further collaboration and in-depth analysis in the future. Subsequently, more input data, further analysis and modelling are needed to mature and qualify a CCUS value chain. Based on the technical screening work performed, the following main recommendations can be made for the further development of CCUS value chains.

• Improve geological knowledge to decrease uncertainties related to storage capacity and leakage risks;