Enemalta yesterday apologised for "any inconvenience caused" by Monday's four-hour electricity blackout but in a statement said it could not be held responsible for the consequences.
Describing the incident as out of their control - a "force majeure event" - the corporation said the shutdown was caused by a technical fault on one of the generating units.
"Enemalta spared no efforts to restore supply in the shortest time possible and without delaying the inconvenience to the industry and the public in general," the corporation said.
Preliminary investigations indicated that a fault developed in the control air system of Boiler 7 at the Marsa power station. The system provides air for the boiler instrumentation, control valves and actuators and any failure results in the automatic shutdown of the boiler.
Unlike the two incidents in June and November last year when the "series of coincidences" and theories of sabotage were not excluded, the government this time accepted the ageing power station was to blame.
The internal reports on both power outages were not released, but Prime Minister Lawrence Gonzi last night ruled out foul play during his interview on the programme Dissett, on TVM.
He said "nothing has resulted" from investigations into possible foul play behind the nationwide power cuts last year.
The government had to be accountable and it had a duty to investigate because there had been a number of coincidences when those power cuts occurred. The fact that there had been no foul play was further evidence of the need to decommission the Marsa power station as soon as possible, Dr Gonzi said.
On Monday, the island was thrown back to the dark ages again when a boiler tripped at around 4.10 p.m., as it was supplying steam to turbines generating 67 megawatts or 25 per cent of the total load required.
The rest was being covered by the Delimara power station but as the 25 per cent load was added to it, Delimara was unable to meet the surge in demand and this resulted in a massive and fast drop in system frequency.
Eventually, this triggered the automatic protection devices, which monitor the system in case of overload, to protect the generators in service by tripping them.
"This led to a total shutdown of all generating plants," Enemalta said.
The corporation said the new generating plant at Delimara would help prevent similar incidents as it would be composed of eight small 18MW generating units, which would limit the impact of a single unit trip to a small percentage of the total load.
Similarly, the planned interconnector from Sicily would provide a source of instantaneous reserve capacity.
On Monday, Finance Minister Tonio Fenech had said the power cut was in "no way similar" to the outages in November and June which were caused by faults in different parts of the Marsa power station.
Meanwhile, the Labour Party yesterday said the blackout reflected the government's lack of timely investment in power generation.
The past two years had seen Enemalta's debts double to €470 million but no significant investment made.
Party spokesman Marlene Pullicino said the government's experts had been warning for years that such an emergency could develop.
The solution that the government had proposed after years of indecision was to invest in an extension of Delimara power station using environmentally-harmful technology.
Situations such as those experienced on Monday put off investors, Ms Pullicino said.