ASSESSMENT OF THE IMPACT OF POWER OUTAGES ON COMMERCIAL CONSUMERS

The effects of electric power interruptions resulting from severe power outages were investigated and analyzed using five cold rooms as a case study. Two approaches have been developed and used. One is based on customers‘ survey that mainly investigates the preparatory actions that a customer may take to reduce the effect of outages. The other one is based on a mathematical model using standard deviation as a measure of dispersion. The spearman‘s correlation factor with the aid of visual basic program was used to X-ray the cost implication involved in running these cold rooms with the utilization of power supply from PHCN to be more economical than powering from individual power generating sets. Furthermore the regression cost analysis showed that cold room 1, cold room 2, cold room 3, cold room 4, and cold room 5 have a spearman correlation factor of 40.04%, 41.93%, 39.16%, 31.97% and 31.09% respectively, which shows how expensive the use of private power source over using PHCN, while the frequency distribution of power outages stood at a standard deviation of 3.78.

Electric power interruptions occur when system capacity, due to severe power outages, is insufficient to meet the system load levels. During these periods of inadequacy, outage costs will be borne by the utility, its customers and perhaps, by’ the entiresociety. The utility outage costs include loss of revenue, loss of future sales and increasedrepair expenditure and maintenance. These costs usually form only a smallpart of the total outages costs. The greater part is that borne by the consumers. Theoutage costs depend on many factors and situations, some of which are discussed inthe following sections. The problem of estimating outage costs is affected by the perceivedcosts of an electric outage and the point in time when a consumer would like tobuy electric energy but is unable to do so. Since there are different classes ofconsumers,each will tolerate loss of service differently. A residential consumer may suffer agreat deal of hardship if an outage occurs during a hot summer day or while he is engagingin domestic activities but it may be of little inconvenience to a commercialuser who is forced to close until power is restored. Also an outage may cause a greatloss to an industrial user if it occurs during the time of the production process. Therefore,consumers do not perceive service interruption to the same degree of hardship.The outage costs to a particular consumer depend also on the alternatives availableto that individual at the time of service interruption. If the outages are not expected,the consumer may have very limited alternatives and may incur a great loss.