Integrated assessment of carbon capture and storage (CCS) in the German power sector and comparison with the deployment of renewable energies

Abstract

If the current energy policy priorities are retained, there may be no need to focus additionally on carbon capture and storage (CCS) in the power plant sector of Germany. This applies even in the case of ambitious climate protection targets, according to the results of the presented integrated assessment study. These cover a variety of aspects: Firstly, the technology is not expected to become available on a large scale in Germany before 2025. Secondly, if renewable energies and combined heat and power are expanded further and energy productivity is enhanced, there is likely to be only a limited demand for CCS power plants, as a scenario analysis of CCS deployment in Germany shows. Thirdly, cost analysis using the learning curve approach shows that the electricity generation costs of renewable electricity approach those of CCS power plants. This leads to the consequence that, from 2020, several renewable technologies may well be in a position to offer electricity at a cheaper rate than CCS power plants. In addition, a review of new life cycle assessments for CO2 separation in the power plant sector indicates that the greenhouse gas emissions from 1kWh of electricity generated by first-generation CCS power plants could only be reduced by 68% to 87% (95% in individual cases). Finally, a cautious, conservative estimate of the effective German CO2 storage capacity of approximately 5 billion tonnes of CO2 is calculated, including a fluctuation range yielding values between 4 and 15 billion tonnes of CO2. Therefore, the total CO2 emissions caused by large point sources in Germany could be stored for 12years (basic value) or for 8 or 33years (sensitivity values).