Examination of the 2006 blackout in Kefallonia Island, Greece

The blackout on the Greek island of Kefallonia on January 24th 2006 was caused by the fall of 10 towers of the 150 kV power transmission network due to high winds and heavy snowfall. These extreme meteorological phenomena were unprecedented on the island and thus had not been taken into consideration by the Greek installation and maintenance regulations regarding these towers. Due to changes in meteorological conditions in recent years, the above regulations have to be revised so as to propose smaller distances between towers in new transmission lines and improvements to the existing lines to endure severe weather conditions when necessary.This paper provides a short description of the High Voltage (HV) network of the island of Kefallonia, the system conditions before and after the blackout, and identifies the causes of the blackout. In addition, the mechanical strength evaluation of the simple circuit towers (similar type to those that collapsed) is made under the stress of gale-force winds combined with the ice-coating of conductors. Finally, in order to avoid the repetition of such an outage, several methods are proposed.

► Presents the events leading to the blackout of the Kefallonia Island in 2006.
► Evaluates the mechanical strength of single-circuit towers under extreme meteorological phenomena.
► Proposes several methods so as to avoid the collapse of towers due to high winds and ice accretions.