Germany's biggest power supplier said on Nov. 15 that human error was to blame for the electricity cut that plunged parts of Western Europe into darkness on November 4. E.ON said the switching-off of an electricity line over the Ems River in western Germany to allow a cruise ship to pass through, coupled with the outage of a second transmission line, "set off the domino effect which led to the temporary disconnection of the European inter-connected power grid."
"Prior to the scheduled de-activation of the ultra-high voltage transmission line that crosses the Ems River ahead of the passage of the Norwegian Pearl cruise ship, the control centre had not checked whether the outage of an additional transmission line might overload the power grid," an E.ON statement said. "About half an hour later, another high voltage transmission line was overloaded for reasons that are not yet known. To compensate for this, a number of lines were switched together at a sub-station." The control center staff assessed that this would decrease the load on the power grid -- in fact, the opposite occurred, which triggered an automatic shutdown procedure, E.ON said.
It ruled out insufficient investment in its technical infrastructure as a cause for the disruption, because all its technical systems had functioned as they were supposed to.
Klaus-Dieter Maubach, the E.ON executive responsible for the power grid, said the company "deeply regretted" the disruption and added that investigations into the incident were continuing. The power outage left 10 million people -- half of them in France -- in the dark and cold on a chilly weekend.
Copyright Agence France-Presse, 2006
