The operation of peaking generating units can be characterized by the
frequency and duration of their operating and nonoperating states and
the transitions between these states. The operating and nonoperating s
tates of peaking generating units can vary significantly depending upo
n their dynamic interactive role within a power system configuration a
nd the numerous constraints limiting their continuous operation. Based
on the Canadian Electrical Association's and Alberta Power Limited's
data collection systems, which define various mutually exclusive avail
able and nonavailable states, this paper will present the results of a
statistical analysis of the states of continuous operation of several
peaking generating units over a period of nine years. The significanc
e of these operational patterns and their statistical characteristics
and the implications for assessing the reliability of peaking generati
ng units will be discussed and referenced in detail. Eased on a histor
ical analysis of generator unit outage statistics, answers to many que
stions posed by utility personnel will be addressed and discussed in s
ome detail (e.g., does the starting probability of transisting from a
reserve shut down state to a fully operating state-vary considerably b
etween generating units and does the duration of operation and reserve
shut down states vary significantly between seasons?). Answers to the
se questions can have a significant impact on generation capacity plan
ning and operating studies. This paper will focus on state transitions
between reserve shut down states and operating states and generator s
tarting characteristics.