The Role of CCS in Power Systems with High Levels of Renewables Penetration

AbstractPast studies have used power plant dispatch models with fixed plant portfolios to demonstrate that flexible capture systems may allow operators to increase profits in current electricity markets by increasing plant output at times of high demand. Some of these studies have also speculated that flexible capture systems may be valuable in future electricity systems with high shares of renewable energy as they could allow fossil fuel plants with capture to rapidly respond to changes in residual load. However, few studies have actually examined the role that plants with flexible capture could play in future power systems. Thus, this study examines the role that power generation with flexible capture systems could play in a future European power system where 80% of generation (by energy) is supplied by renewables. The results show that conventional base- and mid-load capacity decreases while the peak-load capacity (i.e., open cycle gas turbines) increases. In European regions with high shares of renewables, the residual load duration curve become steeper, and hourly changes in residual load increase significantly and happen more frequently at low load levels. The shift towards peak capacity and general decrease in load factors places technologies with high capital costs at a relative disadvantage. In the scenario in which CO2 prices reach 650 per tonne CO2 in 2050, approximately one-fifth of the CCS capacity deployed is equipped with flexible capture. However, in a scenario in which CO2 prices reach € 100 per tonne CO2 in 2050, very little capacity is equipped with flexible capture systems as the cost of emitting CO2 offsets the value of flexibility