Loss of load in an electrical grid is a term used to describe the situation when the available generation capacity is less than the system load. [1] Multiple probabilistic reliability indices for the generation systems are using loss of load in their definitions, with the more popular [2] being Loss of Load Probability (LOLP) that characterizes a probability of a loss of load occurring within a year. [1] Loss of load events are calculated before the mitigating actions (purchasing electricity from other systems, load shedding) are taken, so a loss of load does not necessarily cause a blackout.
Multiple reliability indices for the electrical generation are based on the loss of load being observed/calculated over a long interval (one or multiple years) in relatively small increments (an hour or a day). The total number of increments inside the long interval is designated as (e.g., for a yearlong interval if the increment is a day, if the increment is an hour): [3]
A typically accepted design goal for is 0.1 day per year [10] ("one-day-in-ten-years criterion" [10] a.k.a. "1 in 10" [11]), corresponding to . In the US, the threshold is set by the regional entities, like Northeast Power Coordinating Council: [11]
resources will be planned in such a manner that ... the probability of disconnecting non-interruptible customers will be no more than once in ten years
— NPCC criteria on generation adequacy
Loss of load in an electrical grid is a term used to describe the situation when the available generation capacity is less than the system load. [1] Multiple probabilistic reliability indices for the generation systems are using loss of load in their definitions, with the more popular [2] being Loss of Load Probability (LOLP) that characterizes a probability of a loss of load occurring within a year. [1] Loss of load events are calculated before the mitigating actions (purchasing electricity from other systems, load shedding) are taken, so a loss of load does not necessarily cause a blackout.
Multiple reliability indices for the electrical generation are based on the loss of load being observed/calculated over a long interval (one or multiple years) in relatively small increments (an hour or a day). The total number of increments inside the long interval is designated as (e.g., for a yearlong interval if the increment is a day, if the increment is an hour): [3]
A typically accepted design goal for is 0.1 day per year [10] ("one-day-in-ten-years criterion" [10] a.k.a. "1 in 10" [11]), corresponding to . In the US, the threshold is set by the regional entities, like Northeast Power Coordinating Council: [11]
resources will be planned in such a manner that ... the probability of disconnecting non-interruptible customers will be no more than once in ten years
— NPCC criteria on generation adequacy