Market opportunities for power plants with post-combustion carbon capture

This paper analyzes market opportunities for power plants equipped with post-combustion carbon capture. The focus is on an Ultra Super Critical Pulverized Coal plant and a Natural Gas Combined Cycle plant, which both have flexible CO2 capture (i.e., the capture plant can be turned on and off). In a methodological framework, it is first demonstrated that flexible operation yields higher profits compared to operating strictly with or without carbon capture. The most beneficial operating mode is determined by the ratio between the CO2 and electricity price. Furthermore, a definition is proposed for the marginal cost which can be attributed to the additional capacity which is made available by turning off the capture plant (which could serve as reserve power). A detailed optimization model is employed, to account for the power plants’ technical constraints, and to determine the benefits of flexible capture quantitatively. It is shown that at moderate CO2 prices, capture plants can serve as back-up capacity, i.e., making additional power available by turning off the capture plant can be cheaper than having to start-up and operate additional single cycle gas turbines. Furthermore, the option of turning off the capture plant might avoid investment in additional back-up capacity and could therefore also prove useful at higher CO2 prices.

► Flexible operation of a carbon capture plant can yield higher profits.
► Combination of CO2 and electricity price determines optimal capture mode.
► The option of considering power for capture plants as system's reserves is analyzed.
► Reserve power from capture plants could avoid investment in gas turbines.