According to an online survey conducted among 100 storm personnel from 45 utilities, 87% of the utilities face a large-scale emergency situation at least once a year. For the purposes of the survey, Macrosoft Inc. (Parsippany, New Jersey) defined the term “large-scale emergency outage” as any event that affected greater than 5% of the customers for a period exceeding 24 hours and the magnitude of the outage was significantly high enough to necessitate deployment of a large work force in restoring services.

Conducted in January and February 2006, the survey also found that 15% of the respondents experience an outage situation at least three to five times a year, while 23% said they faced it more often.

Weather — including thunderstorms, hurricanes and winds — was identified as the primary cause of outages. Respondents noted that bad weather is hitting with greater intensity and higher frequency. Utilities in the Mid-Atlantic, Midwest and Northeast face the highest number of emergencies with frequencies in excess of five major events annually. Of these outages, 68% are caused by ice, thunderstorms and winds. The outages typically last for one to three days. Only 11% of the respondents in these regions experienced outages that exceeded five or more days.

By comparison, the frequency of occurrences in the Southern region is less than in other regions, but the duration of each outage event in the South is much longer — five days or more for 43% of the Southern utilities that responded. Of the causes for devastation, 65% are caused by ice, thunderstorms and hurricanes.