Assessment of the Role of CCS in the Provision of Long-Term Security of Power Supply and Deep CO2 Emission Reduction

In order to study cost-optimal power systems consistent with the Paris agreement, a model of the Western-European power system was developed. The model includes a wide range of renewable and non-renewable technology options, assumptions on future techno-economic parameters and demand. Examining the effect of more ambitious emissions targets (net zero to -3.2 Gt CO2 yr-1), it is found that based on cost optimization with base case cost assumptions, bioenergy with CO2 capture and storage and nuclear power generation both play significant roles. Once the available domestic biomass potential is fully exploited for bio energy with carbon capture and storage (up to 5.9 EJ yr-1), direct air capture of CO2 combined with nuclear power as baseload is needed for further negative emissions. With deeper emission reduction targets, the installed capacity of intermittent renewable energy sources like wind and solar photovoltaics decreases as CO2-neutral generation does not deliver the required negative emissions. Finally, it is found that portfolios relying on intermittent renewable energy sources are vulnerable to unfavourable weather conditions, resulting in higher net CO2 emissions and a less reliable power supply.