The total power failure experienced nationwide last Thursday was caused by high voltage, the Transmission Company of Nigeria has said.

The blackout, which occurred around 1.55pm on the fateful day, resulted in a complete system collapse.

TCN said the development made many transmission equipment to explode at Ayede in Ibadan, Oyo State; Osogbo, Osun State; Ganmo in Ilorin, Kwara State as well as Shiroro in Niger State.

Although the firm said it had restored power to most parts of the country, it explained that the damaged equipment tripped a major electricity transmission line, which warranted a total collapse of the grid.

The General Manager, Public Affairs, TCN, Mr. Dave Ifabiyi, said engineers worked throughout the night and into the early hours of Friday to replace the damaged equipment.

Ifabiyi said, in the statement, "The damaged equipment tripped the 330 kV transmission lines from Osogbo in Osun State to Ikeja-West in Lagos State; Benin in Edo State to Omotosho in Ondo State; Omotosho to Ikeja-West and Egbin to Ikeja-West in Lagos State, as well as Okpai in Edo State to Onitsha in Anambra State."

TCN expressed regrets that the repair efforts to restore power supply took a while because of the enormity of the incident.

It apologised to the Federal Government and Nigerians for the inconveniences caused by the outage.

Incessant system collapse prompted the decision of the Federal Government to consider generating additional 4,000 megawatts of electricity from coal two weeks ago.

The Minister of Power, Prof. Chinedu Nebo, said this would augment the country's power generation, which is currently a little above 4,000MW.

Nebo, who said this in Abuja while inaugurating an eight-man committee on the development of a framework for coal to power, said, "The Federal Ministry of Power and the Federal Ministry of Mines and Steel are working together to ensure that not only is coal mined from our coal deposits, but that coal is also converted to power.

"When that is done, it is most likely that these coal belts can give us in excess of 4,000 additional megawatts of electricity. No nation can survive on only one or two sources of energy. If there is sabotage or natural disaster that prevents one source of power, and if that is the only source, then there is problem."