Open Access

Bis vor wenigen Jahren diskutierten vor allem Energieversorger und Umweltverbände über die Abscheidung und Lagerung von CO2. Mittlerweile ist die öffentliche Wahrnehmung von CCS gestiegen. Dabei dürfte die umstrittene Technologie für Deutschlands Kraftwerke weit weniger bedeutsam sein als für energiehungrige Schwellenländer.

The study presents the results of an integrated assessment of carbon capture and storage (CCS) in the power plant sector in Germany, with special emphasis on the competition with renewable energy technologies. Assessment dimensions comprise technical, economic and environmental aspects, long-term scenario analysis, the role of stakeholders and public acceptance and regulatory issues. The results lead to the overall conclusion that there might not necessarily be a need to focus additionally on CCS in the power plant sector. Even in case of ambitious climate protection targets, current energy policy priorities (expansion of renewable energies and combined heat and power plants as well as enhanced energy productivity) result in a limited demand for CCS. In case that the large energy saving potential aimed for can only partly be implemented, the rising gap in CO2 reduction could only be closed by setting up a CCS-maximum strategy. In this case, up to 22% (41 GW) of the totally installed load in 2050 could be based on CCS. Assuming a more realistic scenario variant applying CCS to only 20 GW or lower would not be sufficient to reach the envisaged climate targets in the electricity sector. Furthermore, the growing public opposition against CO2 storage projects appears as a key barrier, supplemented by major uncertainties concerning the estimation of storage potentials, the long-term cost development as well as the environmental burdens which abound when applying a life-cycle approach. However, recently, alternative applications are being increasingly considered–that is the capture of CO2 at industrial point sources and biomass based energy production (electricity, heat and fuels) where assessment studies for exploring the potentials, limits and requirements for commercial use are missing so far. Globally, CCS at power plants might be an important climate protection technology: coal-consuming countries such as China and India are increasingly moving centre stage into the debate. Here, similar investigations on the development and the integration of both, CCS and renewable energies, into the individual energy system structures of such countries would be reasonable.

Among the factors that decelerate progress of CCS demonstration and deployment is the lack of public acceptance of local projects in Germany as well as in other countries. The study presented here aims to take the issue of public CCS perceptions further by empirically investigating the relevance of different specifications of the three main steps of the CCS chain, i.e. capture, transport and storage. An experimental approach is chosen and applied in an online survey with a representative sample from Germany with 1830 participants. With regard to possible CO2 sources we varied whether the CO2 of a specific setting is captured i) as part of an energy-intensive industry process (e.g. production of steel or cement), ii) from a power plant running on biomass, or iii) a coal-fired power plant. For transport, half of the settings described made reference to transport of CO2 via pipelines, the other half did not provide information about transport. With regard to storage the setting descriptions i) either explained that CO2 can be stored in saline aquifers, ii) can be used to enhance gas production from an emptying natural gas field or iii) can be stored in a depleted natural gas field. We find that overall the average of the ratings for perception of the settings fall into the neutral part of the answering scale. If the source of CO2 is a coal-fired power plant the setting is perceived less positively than if it includes biomass or industry. A significant interaction effect between transport and storage specifications is observed. This points out that storage in saline aquifers is perceived more negatively than a combination with enhanced gas recovery while storage in a depleted natural gas field is rated less positively if a pipeline is mentioned and more positively if no transport option is mentioned.