The Economic Value of Flexible Ccs in Net-Zero Electricity Systems the Case of the UK

We build a unit-commitment optimization model of a flexible combined-cycle gas turbine (CCGT) with solvent-based post-combustion carbon capture and storage (CCS). We derive the economic benefits of a CCS with solvent storage for a 20-year investment (2030-2050), based on the expected long-term increase of carbon prices and the volatility of electricity prices. Drawing on National Grid’s Future Energy Scenarios for the UK, our model shows that the CCGT-CCS plant profit is, on average, higher with the solvent storage, because of intertemporal arbitrage opportunities created by having this storage solution. We further showed that the economic value of this intertemporal flexibility increases with higher electricity price volatility. Under high price volatility, the total return on investment (ROI) could reach 81-246%. In relative terms, this is much higher than the total ROI of the CCGT-CCS plant itself (7-64%).While there is an economic case for investing in flexible CCS with solvent storage, there are wider system benefits too. This solvent storage flexible solution should be seen in the context of overall system ‘flexibility’ requirements of a low-carbon power system. On cost basis, the solvent storage represents just a fraction of the capital costs of some of the “mainstream” energy storage technologies, such as lithium ion batteries or hydro pumped storage while CCGT-CCS is firm power. Overall, while seen as a rather technical solution, if abated fossil fuel generation is to be part of a future low-carbon power system having this flexibility adds economic benefits not just to operators but also improves overall system security and compliments high share of variable renewable