Analysing the sensitivity of electricity system operational costs to deviations in supply and demand

Increasing renewable penetration has given rise to a series of challenges as regards the ability of electricity systems to balance supply and demand, particularly with high levels of intermittent renewable generation. This new scenario requires a detailed quantitative assessment of the way in which the electricity system might both deliver and accommodate higher levels of RES-E generation and of the associated economic costs for the consumer. The estimations reported in this paper for the Spanish electricity system stress the importance of demand imbalance when accounting for the cost of balancing services, in contrast with previous studies that have focused their attention more specifically on supply effects.