Published on November 26th, 2012 | by Guest Contributor


Most Powerful Blackouts In History

November 26th, 2012 by  

Here’s an interesting look at an issue that can cause a lot of chaos. Notably, the increasing use and development of microgrids, which are a perfect fit with decentralized energy sources such as wind and solar, is one key solution to blackouts, as is the development of “smarter” grids.

Post updated extensively on November 27, 2012.

Blackout via Justin in SD (some rights reserved)

Blackouts can affect millions of people. They can last for days or even weeks, causing chaos throughout cities and entire regions. They often occur following natural disasters, and can add to the damage caused by the original disaster.

Here is a look at some of the most powerful blackouts in history:

India Blackout, July 2012

July was a bad month for India as the country experienced its worst blackout ever. 670 million people were affected — that’s more than two times the population of the United States. The outdated electrical grid was blown due to the large number of people using air conditioners and other electrical appliances.

The Metro shut down for several hours and people were forced to deal with the oppressive heat as the sun came up. It was restored quickly but a second outage soon followed and this was also widespread.

Java–Bali Blackout, August 2005

This blackout in the middle of August 2005 caused Jakarta, the capital of Indonesia (the fourth most populated country in the world), to lose power, as well as several other cities and most areas of Java. In total, approximately 100 million people were affected. That’s approximately 1/3 the population of the United States, and almost half the population of Indonesia.

Southern Brazil, March 1999

Southern Brazil was hit by what was the largest blackout in history at the time back in March 1999. It was isolated to Southern Brazil but it affected approximately 75-97 million people. A lightning strike started this blackout, which brought down the largest power plant in the world at the time, Itaipu. “In Rio the military police placed 1,200 men in the streets to avoid looting. In São Paulo, traffic authorities announced they closed the city’s tunnels to prevent assaults. More than 60,000 people were on Rio’s subway when lights went out.”

Brazil/Paraguay, 2009

This blackout affected large parts of Brazil and practically the entire country of Paraguay. Passengers on metro trains were stranded and there were numerous car accidents due to the lack of street lighting.

Buses had a difficult time handling the extra passengers and many people were left with no way to get home. Even though the blackout only lasted a few hours, approximately 87 million people were affected. Storms were responsible for the outage.


Northeast U.S. & Canada Blackout, 2003; Italy Blackout, 2012

The Northeast U.S. & Canada blackout of 2003 and the Italy blackout of 2003 were incidentally approximately the same size, in terms of people directly affected. Each resulted in about 55 million people losing power.

In the North American blackout, many residents did not get their power turned on for a couple of days. Approximately 45 million Americans and 10 million Canadians were affected by the blackout, which was reportedly started by lighting striking a power plant in northern New York.

The Italy blackout was caused by a power line between Switzerland and Italy going out for a few hours. 110 trains were shut down and 30,000 people were stranded on them. All Italy flights were cancelled. “The night of 27 September 2003 is the night of the annual overnight Nuit Blanche in Rome, the capital of Italy. Thus, many people were on the streets and all public transportation were still operating at the time of the blackout (at about 03:00 on 28 September 2003) despite the fact that it was very late at night. The blackout caused the carnival to end early. Several hundred people were trapped in underground trains. Coupled with heavy rain at the time, many people spent the night sleeping in train stations and on streets in Rome.” Luckily, there were reportedly no serious accidents! The only non-Italian area that was affected was part of part of the Geneva Canton of Switzerland, and just for a few hours.

Northeast U.S. Blackout, November 1965

A blackout that led the record books for years, the Northeast U.S. blackout of 1965 left about 30 million people without power for up to 12 hours. The cause of this one? Human error. “Maintenance personnel incorrectly set a protective relay on one of the transmission lines between the Niagaragenerating station Sir Adam Beck Station No. 2 in Queenston, Ontario. The safety relay, which was to trip if the current exceeded the capacity of the transmission line, was set too low…. New York City was dark by 5:27 p.m. The blackout was not universal in the city. Some neighborhoods never lost power. Also, some areas in New York City suburban area Bergen County, New Jersey, served by PSE&G, did not lose power. Most of the television stations in the New York metro area went dead, as well as about half the FM stations.” The good news in this story was that it occurred during a full moon, which provided highly needed light, if not as much as would be ideal for most of the city-dwellers.

2012 U.S. Blackouts

Some other notable blackouts that did not directly affect as many people as those above but which had a strong impact on key economic areas of the U.S. include two from just the past year:

East Coast United States, July 2012

This was the largest non-hurricane blackout in history for the United States. Caused by several violent storms, four states and the District of Columbia were affected. Call centres were out of commission for emergencies and petrol (gas) stations were closed down.

The government requested that people conserve water due to sewage plants being out of operation. To make things even worse, many people had to suffer through a heatwave that followed the storms with no air conditioning. [Editor’s note: one of our writers was in that boat! Not fun.]

East United States, October 2012

The East Coast of the United States got hit with a second outage, this time in New York and other areas that were affected by Hurricane Sandy. Millions were without power for days; over 250,000 homes were affected in New York City alone. For the entire state, over one million were without power, while 14 states had some outage of power from the storm.

The state least affected was North Carolina, with 6,600 homes without power. Some homes were still without power two weeks after the storm, right when a large snowstorm hit the area, further complicating clean-up operations.


Blackouts can last from a few hours to over a week, depending on the cause and the infrastructure of the nation in question. Regardless of how long they last, the resulting damage can be widespread and severe. For more information on how to cope with a blackout by using emergency power, visit Mather and Stuart.

Check out our new 93-page EV report, based on over 2,000 surveys collected from EV drivers in 49 of 50 US states, 26 European countries, and 9 Canadian provinces.


About the Author

is many, many people. We publish a number of guest posts from experts in a large variety of fields. This is our contributor account for those special people. :D

  • Pingback: Marcacci Communications()

  • Lundberg

    Nuclear power is sometimes a cause of blackouts, because a scram is ususally not anticipated and can mean that 1000 megawatt is lost from one second to the next. Reactor also tend to trip if the grid is unstable. It is difficult to bring the reactor to a state where it supplies steam for its own needs, no more, no less. If this state “in-house turbine” is not achieved, the reactor will be down for several hours.

    Nuclear power explains much for the two biggest blackouts we have had in Sweden in for a very long time, in 1983 and 2003. The first one was not caused by nuclear, but was much aggravated by it.

    Is this a general pattern or not, for example in India 2012?

    • I’m not sure of any links between actual blackouts and nuclear, but nuclear clearly has some big weak spots that hardly get any mention. A decentralized grid is much safer and more stable. I know US security forces have been pushing for more decentralization and microgrids. Of course, behemoth nuclear power plants don’t fit that bill. They also have very long start & stop times, which causes problems with a grid increasingly focused on variable renewable resources.

  • jonesey jonesey

    July 2012 “the largest non-hurricane blackout in history for the United States”? Have we forgotten August 2003 already? 1965? Even the September 2011 Southwest blackout was about the same size as July 2012.

    And the India blackout was the largest in world history by a factor of about 6, not just in the last 10 years in India.

    Any of this information could have been fact-checked with a quick visit to Wikipedia:


    I’m finding that CleanTechnica is a mix of articles, some loaded with information and facts that I can’t find anywhere else, and some that are pure WTF that appear to be copied and pasted with no fact-checking or thought put into them at all. I prefer the former type.

    • Will try to do better on the fact-checking. Editing 10-15 articles a day (on top of plenty of other duties) and not being a specialist in every single one results in some things slipping through the cracks. Thanks for the info here — will try to get the post corrected.

    • extensively updated now. i will try to be *much* more attentive with these guest posts, which are often the ones that are on subjects I don’t follow as closely. thanks again for the note.

Back to Top ↑