Blackout Watch

System Power Outages

Author: Clare Duffy, ESBI, Ireland

Analysis of system power outages can help us learn and avoiding similar events in the future. If you have information on any blackouts, please e-mail to

Los Angeles, California, USA:  The Los Angeles Department of Water and Power (LADWP) reported approximately 129,000 of its 1.4 million electric customers lost power as high winds swept through the city. In some areas, winds reached up to 97 mph, as LADWP confirmed they had an incident at one of their power receiving stations. Los Angeles International Airport (LAX) also suffered a power outage, delaying flights at one of the nation’s busiest airports for over one hour.

Accra, Ghana:   A nationwide power outage swept across Ghana for close to four hours after one of the breakers in the Switch Room of the Volta River Authority (VRA) exploded. This led to a countrywide outage and widespread panic amongst residents. This incident was the first time in eight years that Ghana, a country of nearly 25 million people, experienced a power failure of this magnitude.

Wellington, New Zealand:  The sudden failure of the Huntly power station at about 12:30pm local time triggered an automated safety mechanism which cut power to roughly 200,000 homes and businesses. The loss of the New Zealand’s largest power station from the network caused the frequency at which electricity is transmitted to drop suddenly, which could have caused the collapse of other generating plants. Transpower, the national grid owner, ordered the shedding of 16 percent of customers load, which may have prevented the entire North Island from losing power. 

San Francisco, California, USA:  Two major power outages delayed a prime-time football game between the hometown 49ers and the Pittsburgh Steelers, after a transformer exploded just before kickoff, leaving the crowd of 69,732 sitting in darkness. A 49ers spokesman said city engineers worked swiftly to switch the power to backup generators, which restored power until early in the second quarter, when the power again failed and delayed the game. Pacific Gas & Electric Co. said they had made all of the routine checks earlier in the day and that all systems appeared to be in order. The power company was still investigating the cause of the outage.

Helsinki, Finland:   A major snowfall and high winds were blamed for a power outage which lasted several days in many areas of southern Finland. Approximately 200,000 customers were without power when lines were damaged throughout the region. Repairs were slowed by poor weather, with only about 20,000 per day seeing their power restored.

Istanbul, Turkey:   A failure on a main power transfer line running from Bursa to Istanbul was blamed for a major blackout that left up to 20 million people without power. The outage is reported to have also affected regions around Istanbul, such as Edirne, Kocaeli, Sakarya, Kirklareli and Tekirdag. Power began to be restored to the eastern portion of the city after approximately one hour. Bulgarian Focus Information Agency reported that Turkey reacted by importing electricity from Bulgaria.

Bangalore, India:  The city of Bangalore experienced a major blackout for at least one hour after a technical glitch occurred at Sarakki Station. The city of eight million suffered a power loss that was worst in the southern parts of the city.
Sao Jose, Brazil:   The 500 kV Angra – São José transmission line (TL) was tripped due to an internal fault that occurred during tree pruning services in the line right of way. At the same time the 500 kV TL Adrianópolis – São José was also tripped. The loss of two in five 500 kV lines to Rio de Janeiro metropolitan area led to automatic load shedding in part of non-priority loads of the two local distribution utilities, in response to the actuation of the area special protection scheme. The amount of load shed was around 1,488 MW, affecting 840,000 electric energy consumers. After 19 minutes the 500 kV TL Angra – São José was back to service and at 11:26 the electric energy supply was restored to all consumers. At 11:33 the 500 kV TL Adrianópolis – São José was restored as well.

 Sao Jose, Brazil:   On the same day, a little bit earlier, at 10:00 am, the 500 kV TL Adrianópolis – São José had been tripped for fault in the 138 kV TL#1 São José – Triagem, without adverse consequences to Rio de Janeiro metropolitan area. The 500 kV line was reenergized at 10:14 AM.
Later on that day, the transmission utility found a defective static relay at Adrianópolis terminal of 500 kV TL Adrianópolis – São José, which caused the incorrect tripping commends for external faults.


Power. Flexible. Easergy.
Let?s start with organization in protection testing