The Maxi Blackout that hit Spain, Portugal and the south of the France Yesterday, paralyzing trains, planes, telephone networks and Internet networks, seems to be largely returned, with the 99.95% of the national energy needs restored. In Italy the news brought to memory the memory of the more serious blackout ever in Italian soilwhich dates back to the night between 27 and the September 28, 2003when a large part of peninsular Italy remained without electricity at 3:27, causing the interruption of air and rail transport and the blocking of elevators. The accident lasted about 12 hours. Often it is simplified by saying that it was “The fault of a tree”but the reality is more complex.
The causes of the blackout in Italy of 2003: it was not just a fallen tree
In 2003 the Italian electrical system highlighted on energy imports. About the 17% of the national energy needs was covered by foreign supplies, in particular by Switzerland and France. The blackout was triggered by a fault on one High voltage line in Switzerlanddue to contact of a tree with cables electric from 380 kV in the Canton Ticino. But the real problem was the delay in the management of the emergency by the Swiss manager Etrans (Today Swissgrid) and the subsequent chain reaction that overloaded the other lines. In a few seconds the system lost stability: the electric frequency collapsed, the generators lost the necessary synchrony and the protection systems gradually detached the network.
Electric networks are extremely rapid systems. When a line falls, the electrical flow is poured on the remaining lines, which in turn can go overcarically. If the management is slow or ineffective, a Blackout in Cascata: This is exactly what happened in 2003 in Italy, like yesterday in the Iberian peninsula.
However, a tree is not enough to turn off an entire country: one is needed system vulnerability. The 2003 blackout was in fact caused by several other contributing: a high dependence on the import of energy from abroad; a not sufficiently robust transmission network; delays in communication between network managers; absence of automatic rapid stabilization systems.
What changed to Italy after 2003
After that event, Italy has greatly improved its system:
- Greater internal production, especially renewable;
- Enhanced and more resilient electric networks;
- Automatic response systems and more advanced real -time monitoring;
- Much closer European coordination (also thanks to organisms such as Entso-E).
Today the risk of a total blackout is much lower, but it is never completely zeroed.
