Opportunities for applying solvent storage to power plants with post-combustion carbon capture

One way of implementing Carbon Capture and Storage (CCS) on fossil fired power plants is by means of post-combustion capture. Regenerating the solvent and compressing the CO2 in this process requires a significant amount of energy and therefore increases the cost of the produced electricity, as less electricity can be sold. By implementing solvent storage, this energy penalty can be delayed until moments with a low electricity price (i.e., more electricity could be sold when the electricity price is high and less when the electricity price is low). Investing in solvent storage, however, is only profitable if the profit increase is sufficiently high. This paper presents an analytical optimization framework for solvent storage implemented on a coal-fired power plant in an electricity market with a methodological, two-step electricity price profile (peak and off-peak). This analysis identifies distinct ranges of peak and off-peak price combinations in which solvent storage can lead to an increased profit. Depending on the problem parameters, these price ranges can vary, mostly depending on the emission certificate cost and the investment cost of the solvent storage infrastructure.