ISTANBUL/BRUSSELS (Reuters) - A power outage that blacked out most of Turkey on Tuesday was not due to a cyber attack and will not threaten a deal to link up with European grids, leading energy officials said.
The major outage hit Turkish cities and provinces, including the capital Ankara and Istanbul, where parts of the metro system shut down for several hours and shopping malls were plunged into darkness.
"We have not come across any evidence of this outage being caused by a cyber attack," a senior Turkish energy ministry official who took part in resolving the outage told Reuters.
He identified faults at two plants as the cause, at Izmir and Adana Cukurova in the Aegean and Mediterranean provinces respectively.
"This would mean a 5-10 percent cut in the capacity of the system," the energy official, who declined to be named, said. "This reduction created a domino effect on the whole system and shut it down."
On April 15, Turkey's transmission system operator TEIAS is set to sign a long-term agreement for a permanent connection to the continental European grid, following a trial period that started in September 2010.
Tuesday's massive blackout should not jeopardize that, the head of Europe's grid operators organization told Reuters.
Konstantin Staschus, Secretary-General of the Organisation of European Transmission System Operators for Electricity ENTSO-E, said that Turkey's blackout had shown there are adequate safeguards in place to prevent contagion.
The connection with Europe also helped Turkey recover faster than it would have otherwise, he said.
"The protection schemes have worked, the disturbance did not spread anywhere in Europe. From that perspective, the signature should go forward as planned," he said.
"Excluding Turkey from the system or a delay in the signing of the long-term agreement this month is out of the question," the Turkish official said.
Staschus said that the existence of the EU connection had helped Turkey restore power and that Thrace, the part of Turkey on the European continent, had come back online first.
Turkey and Europe are connected with synchronous alternate current (AC) lines, which means their power systems operate on the same frequency.
This allows neighboring regions to share power reserves and act as a back-up for one another.
"There is always a risk in the sense that a disturbance in one system can spread to other systems, but the economic benefit of connection far outweighs the risk," Staschus said.
Continental Europe also has synchronous AC connections with Morocco, Algeria and Tunisia via the narrow strait of Gibraltar.
But several European countries such as Britain, Ireland, the Baltic states and the Nordic states are connected to the continent via direct current lines, which work better for subsea cables and long-distance connections.
Editing by William Hardy