Following several widespread and national power outages in a few weeks, Enemalta said that an undersea cable connecting the Maltese national grid to the European energy network was completely out of action and will take an indefinite amount of time to fix. But many questions remain.
Times of Malta sought an explanation from the energy company.
Q. Interconnector trenches are installed in specially dug trenches to avoid damage caused by ships’ anchors. According to Enemalta, the damage also occurred 150 metres under the surface of the sea and this has raised doubts about why ships would carry such long anchor chains. What is Enemalta’s explanation?
A. As indicated on Monday, at this stage we suspect that the damage was caused by a ship anchor. The survey should help establish facts more clearly. The submarine cable lies on a sandy seabed, which cannot be trenched, rather, the cable was laid using a jetting process technology whereby the sandy seabed is spread reaching a depth of approximately 1.5 metres, the submarine cable is laid, and then covered by sand.
Q. The authorities had said that the main sources of power would be Delimara III (BWSC) and Delimara IV (Electrogas), while the interconnector was never meant to be the main source of power. Once the interconnector was damaged, we started experiencing outages. Why have we been relying on the interconnector for the generation of electricity?
A. The sources of electricity supply, apart from the Enemalta emergency backup generation plant, available to Enemalta to meet local load are photovoltaics generation, Delimara III, Delimara IV, and the interconnector.
The sources, including the interconnector, are dispatched by Enemalta according to prevailing technical and economic requirements.
During 2019, the percentage of total load generated by the different sources was as follows: 6.7 percent photovoltaics, 13.9 percent Delimara III, 53.8 percent Delimara IV, and 23.1 percent interconnector. The remainder was generated by the Enemalta emergency backup generation plant.
Q. The power demand nowadays stands at 390MW, while it has been suggested that once factories return from the Christmas shutdown, demand will increase to 450MW. Enemalta has said that excluding the interconnector, it has a total generation capacity of 533MW. Why then, are we still experiencing blackouts? Are the remaining units delivering their full rated capacity?
A. While the indicated figures are correct, the three instances of load shedding experienced since last Friday were precipitated following separate faults that developed on the dispatched generation plant. In each case, the faulty generation plant was subsequently made available for dispatch, so that available capacity has been restored to 533MW.
Q. Enemalta said the Electrogas plant has also suffered some damage. What is the damage and when is the unit expected to be in service at full capacity?
A. The faults sustained by the Electrogas Delimara IV machines were not the result of damages sustained by the plant. Rather, the failures of two different units - one on Friday and the second one on Monday - were caused by different faults that developed on the respective control and monitoring systems. In each case, the machines were made available and put back in service within a short time. Presently, the full 210MW capacity of Delimara IV is available for dispatch by Enemalta.