Evaluation of reliability worth and value of lost load.pdf

Evaluation of reliability worth and value of lost load K.K. Kari uki R. N.AI Ian Indexing terms: Reliability, Reliabilit indices, Customer interruption costs, Compositecustomer damagefiction, Customer outage costs, Incremental customer outage costs, Value of lost Lad the overall behaviour of service areas or systems. In the Abstract: Customers’ perceptions of reliability UK, nationwide fault statistics collected under a may not always reflect the level of reliability national fault and interruption reporting scheme are purported by traditional reliability indices. This used to calculate these indices. The most widely has been recognised and efforts have been made reported performance indices, availability and security, by the electricity supply industry (ESI) in the are defined as the minutes lost per customer and the United Kingdom to relate ‘reliability investment’ number of supply interruptions per 100 connected con- with customers’ marginal benefits obtained from sumers, respectively. These indices provide useful infor- such investment. A difficulty encountered during mation to the utilities and the regulator on the such earlier and recent efforts has been the lack performance of each public electricity supplier (PES). of appropriate valuation of these benefits. With a From the customers’ perspective, their perceptions of view to correcting this paucity, the authors have reliability are influenced by, conducted studies, based on custom