A cable fault that triggered the nationwide electricity blackout in August escalated after the battery that powered protective systems at a distribution centre failed.
An Enemalta inquiry into the power cut that left a number of localities without electricity for 18 hours found that different levels of protective systems installed at the Marsa South distribution centre did not operate.
“The cause of this failure was a fault in the direct current supply to the protection and control system at Marsa South distribution centre,” the inquiry board found.
Times of Malta was only given access to the executive summary and the recommendations made in the inquiry report. Enemalta cited commercially-sensitive information when asked for the full report.
The inquiry board concluded that the incident was purely technical in nature
Part of the distribution centre burst into flames after an explosion caused widespread damage to the switchgear.
The report said the original fault happened at a joint on a cable running between the distribution centre and a substation in Paola.
This caused the current on the network to surge, which led to the damage at the distribution centre.
Mechanisms to safeguard the power stations from the surge did kick in, which eventually led to the blackout.
The inquiry board concluded that the incident was “purely technical in nature”.
It recommended that the main distribution centres be equipped with “a main and standby battery bank”.
“The two batteries are to normally operate in parallel; however, a facility should be provided to permit the testing of one battery bank while the other still supports the control voltage requirements of the distribution centre,” the board said.
Another recommendation calls for the installation of standby generators at distribution centres that did not have one. It is unclear whether the Marsa South centre had a generator.
The board asked for an audit of the layout of distribution centres to ensure that a fire within a section did not spread to other areas.
An audit of combustible materials in switchgear rooms was recommended to establish the appropriate firefighting systems to mitigate the spread of fire.
The board called for response plans and drills to be drawn up or updated so that “responsibilities are clear during the restart”.
Again, it is unclear, since the whole report was not made available to this newspaper, whether this recommendation was made because response plans at the Marsa South centre were inadequate.
The inquiry board was set up after Malta and Gozo were plunged into total darkness on a hot August evening.
While power was restored to most localities in a matter of hours, residents in Qormi, Luqa, Siġġiewi and Marsa that were directly connected to the distribution centre, had to wait 18 hours until the building was certified safe.
About 8,000 households that remained without electricity for more than 12 hours were eventually granted a €25 reduction in electricity bills as compensation.
Additional reporting Ivan Martin