The Good Friday power cut came about because the evening demand for power spiked to 11.5MW, which was twice the spinning reserve capacity of 5MW, the Finance Ministry said today after receiving a report from an internal Enemalta board.

Spinning reserve capacity is the capacity immediately available to be put on the distribution network.

The Finance Ministry said that before the total power cut, electricity demand was of 210MW, of which 153MW were being generated by Delimara power station and 57 by Marsa power station.

At 7.27 the spinning reserve capacity was of 5MW.

The ministry said that as was normal procedure, an order was issued to switch on turbine JB2 at Delimara to keep up with demand. The ministry said that the precise load demand can never be accurately gauged and engineers made their professional judgement based on historical data.

However, last Friday, demand rose to the extent that the turbine could not be synchronised with the required frequency in view of the abnormal conditions on the network.

The load between 7.27 and 7.37 p.m. increased by 11.5MW, more than twice the reserve of 5MW, leading to a shortfall in generation and, eventually, a drop in frequency.

The ministry said that the internal board which had investigated what happened had noted that industrial action directives ordered by the GWU had affected communication between the two power stations and the management of the situation.

The engineer at Marsa power station started switching off a number of feeders but that was not enough to avoid the tripping of the whole system owing to voltage fluctuations.

The board in its report to the ministry recommended that the spinning reserve capacity should be of 10MW instead of 5MW so as to allow a greater safety margin in case of unexpected demand ,and independent load shedding should be considered.

The board also recommended that industrial action directives which limited communication between the workers in the generation sections should not be allowed.

The authorities should also address the direct responsibility of the engineers at the time of the incident.

Finance Minister Tonio Fenech has accepted the recommendations and requested that they be addressed immediately.