Cyberattack a possible cause of South America's power outage, says Argentina

Five countries were affected by the grid failure on Sunday morning

Technicians of Edenor electricity company stand under the rain as they work to fix a generator during a blackout in Buenos Aires, Argentina. AP

A pizza maker uses battery powered lamps to illuminate his work space during a blackout inside the delivery-only pizza shop in Buenos Aires, Argentina. AP

Cars drive through an unlit street during a blackout in Buenos Aires, Argentina. AP

A polling station is seen during a national blackout in Rosario, Santa Fe, Argentina . Reuters

A polling station is seen during a national blackout in Rosario, Santa Fe, Argentina. Reuters

People look for their names in a voters list at a polling station during a national blackout in Rosario, Santa Fe, Argentina. Reuters

A vendor waits for customers during a national blackout, in Buenos Aires, Argentina. Reuters

A man stands at the Aristobulo del Valle train station during a national blackout, in Buenos Aires, Argentina. Reueters

View of a polling station for Governor elections among a power outage in Rosario, Argentina. EPA

Sweets for sale are seen inside a store lit by candlelight as the neighbourhood Parque Batlle goes without electricity, although power has mostly been restored after a massive blackout in Argentina cut electricity to much of neighbouring Uruguay and swaths of Paraguay, in Montevideo, Uruguay. Reuters

People check for their voting desk in Governor elections among a power outage in Rosario, Santa Fe province, Argentina. EPA

A lamppost shines down a street as the rest of the neighbourhood Parque Batlle goes without electricity. Reuters

A man looks at his phone before casting a vote at a polling station during a national blackout, in Rosario, Santa Fe, Argentina. Reuters

Argentina said it isn’t ruling out a cyberattack after what President Mauricio Macri called an “unprecedented” power blackout struck five South American countries on Sunday.

Mr Macri said Argentina is investigating the incident, which began with an as yet unexplained fault in its power grid that led to outages in Argentina, Uruguay, Brazil, Chile and Paraguay.

Though a cyberattack isn’t the primary hypothesis, it can’t be ruled out, Argentine Energy Secretary Gustavo Lopetegui told reporters in Buenos Aires. A “technical issue” or simple humidity could have triggered the breakdown, said Carlos Garcia Pereira, head of Transener, Argentina’s largest power-transmission operator.

“This morning, a fault in the coastal transmission system caused a power outage in the entire country, whose cause we cannot yet determine precisely,” Mr Macri said in a series of comments on Twitter. “This is an unprecedented case that will be thoroughly investigated.”

Paraguay’s National Electricity Administration said the breakdown began with an event in Argentina’s power network, which led to a fault that disconnected all generators at the Yacyreta hydroelectric dam from the regional grid on Sunday morning.

Underscoring the vulnerability of cross-border grids to local glitches, the outage disrupted regional elections in Argentina and cut off power for millions in South America’s second-biggest economy. The integrated nature of the regional grid meant that the interruption also affected Brazil, Chile and Paraguay, Uruguayan state utility UTE said in a statement.

That chain of events was “abnormal,” Mr Lopetegui said.

Electricity was restored in about half of the affected areas in Argentina by 2:30pm local time, more than seven hours later, and is now 100 per cent restored, according to the Energy Ministry. Power has been restored to 99 per cent of clients in Uruguay, according to state-owned utility UTE.

The blackout delayed voting Sunday in gubernatorial elections in Argentina's provinces of Santa Fe, Formosa, and San Luis. Voters marked ballots by candlelight or using their mobile phones as flashlights amid an "emergency protocol," newspaper Clarin reported.

Gubernatorial elections in Tierra del Fuego in the south were unaffected by the outage because the province is separate from the rest of the country’s grid.

Businesses that were normally open on Sundays stayed shut. Phone service was also intermittent. Several panoramic photos shared on social media showed huge swaths of Buenos Aires with no lights on.

“When I started my work we didn’t have any electricity in the building, the streets were empty, not a single business was open,” Buenos Aires resident Maria Carrera said by phone around noon. “I haven’t been able to cook breakfast, and we still don’t have any power.”

The outage was set off by a fault affecting Yacyreta’s transmission system, causing power to be cut automatically and triggering a grid failure at 7:07am local time in Argentina, the Energy Secretariat said. That incident led to generators at a hydroelectric plant on the border of both Paraguay and Argentina suddenly going off-line.