Power Blackout Risks

blackout 2003, italy/swiss
17/18/19
 
what happened?
•
28th September 2003: Italian power system faced its worst disruption in 50 years, which also affected
parts of Switzerland with 56 million people in total
•
Electricity was restored after 1.5 hours (CH) and 18 hours (Italy)
causes:
•
Inability of the Swiss system operator to reclose the Mettlen-Lavorgo line after its initial failure.
•
Ineffective communication and subsequent slow and ineffective emergency responses by the Swiss
and Italian system operators.
•
Angle and voltage instability in Italy just prior to its collapse. 
•
Insufficient tree cutting under the power lines. 
impacts:
•
Beside Switzerland and Italy, the networks in France, Slovenia, and Austria were affected and the blackout
led to a domino effect that ultimately resulted in the separation of the Italian system from the rest of the 
European grid. >
17
Project Understand, White Paper on Security of European Electricity Distribution, 20.6.2007
(http://www.understand.se/docs/White_Paper_EN.doc)
18
http://www.solarstorms.org/Italy2003.html
19
http://www.semissourian.com/story/121022.html

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28
•
30,000 people were trapped on trains. 
•
Several hundred passengers were stranded on underground transit systems.
•
Significant knock-on effects across other critical infrastructures, commercial and domestic users which 
suffered disruption up to 48 hours.
•
Subway had to be evacuated. 
•
Cost to restaurants and bars in spoiled products and lost sales totalled up to USD 139 m.
blackout 2006, germany incl. western europe 
20/21/22/23

what happened?
•
On November 4, 2006 the German TSO E.ON Netz had to switch off a high voltage line to let a ship
pass underneath.
•
Simultaneously there was a high amount of wind electricity which fed into the grid 10,000 MW from
wind turbines to Western and Southern Europe grids.
•
Insufficient communication about this switch-off led to instabilities of the frequency in the grid and
to overloading of lines. 
•
Devices had to switch customers off in the countries affected to cope with this lack of power in the
Western zone automatic.
•
The blackout lasted up to two hours.
causes:
•
After manual disconnection of the high-voltage line the n-1 criterion of process security was not fulfilled.
N-1 criterion means that any component may fail and all other components are still below their limit.
As a result, even a relatively small power flow deviation could trigger the cascade of line tripping.
•
Insufficient co-ordination between transmission system operators.
•
No access to real-time data from the power units connected to the distribution grids.
•
Lack of joint simulation training with neighbouring transmission system operators.
•
Lack of coordination between operators’ internal procedures regarding grid-related, market-related and
other adjustments.