Generation system reliability in a market environment

In liberalized electricity markets, one of the most important questions nowadays is to balance the contradicting requirements of reducing cost and of securing or even increasing power quality at the same time. In this context, also the effect of the reliability of the power generation system on the supply reliability delivered to the customers is of interest. While the influence of the generation system on overall supply reliability in typical western European public networks is quite small, the situation may be different for special situations such as industrial customers or regional utilities with significant own generation capacity. Apart from the technical influences on supply reliability, in the liberalized context also the economical influences are important. Typically, economical influences of outages in the generation system - but also deviations from planned schedules can quickly reach significant levels for affected utilities or industrial customers with own power generation. The paper shortly describes basic aspects of probabilistic reliability calculation and then focuses on economical correlations. Examples demonstrate the presented aspects.