Sabah Electricity Sdn Bhd (SESB) Managing Director Abd Razak Sallim said the system was designed such that the kind of problem which led to the power failure should not have brought the whole system down.
Hospitals were forced to rely on generators while in most places motorists were left to figure out how to avoid accidents at traffic intersections on their own as traffic police were stretched.
Only two months ago, Green Technology and Water Minister Datuk Maximus Ongkili had promised that the blackouts would end with RM1.4 billion to be spent on replacing hundred of kilometres of cables over a five-year period.
The current cables were susceptible to power interruptions when in contact with objects like tree branches.
In the latest case, a fault in one of the two transmission lines between Universiti Malaysia Sabah and Ungun in Sepanggar at 10.56am set in motion what turned out to be a massive blackout which left some 500,000 people fuming.
Power resumed in stages but was only expected to be fully restored by 9pm. Labuan saw power restored within an hour. Abd Razak said the fault could have been caused by a foreign object or the system itself.
"This was cleared within 100milisecond but a second after that, one of the Independent Power Plants in Ungun, Sepanggar, tripped resulting in the loss of 200MW which subsequently caused our power plant at Patau-Patau in Labuan to also trip," he said.
"Our generators were supposed to be able to withstand up to 150milisecond and the most critical is up to 475milisecond. However, a trip happened after one second of that fault," he said during a 3.30pm media conference held at Wisma SESB.
"This caused us to lose about 353megawatt which is about 50 per cent of whole system," he said. During the press conference at Wisma SESB, power from the generator also, ironically, tripped twice.
Prior to the system collapse, SESB was supplying a total of 877MW, which was 146MW more than the 731MW demand. He explained that following a massive power outage in 2012, SESB found that there were several issues that needed to be addressed in terms of system coordination.
"We addressed this issue and based on our SAIDI (System Average Interruption Duration Index) last year, the system is now more stable but now there is still more to be done because the demand profile characteristics change from time to time," he said.
"We have worked with the Energy Commission and Tenaga Nasional Berhad to identify a better approach in strengthening the system which is an on-going process which we hope will bring further improvement in future," he said.
Abd Razak said on Friday their Emergency Response Programme plan was immediately activated in islanding mode (regional mode) Statewide, namely Melawa, Salut, Labuan, Pangi, Tawau and Sandakan.
The first restoration was achieved one hour later in Ranau at about 12.15pm and subsequently in Tawau and Labuan at 1pm, Keningau at 1.50pm and Semporna at 1.55pm.
"As of now, power is 70 per cent restored throughout Sabah and we hope to fully restore the power by 9pm once all our generators are stable," he said, adding that this has no connection to last year's power outage which was caused in Penampang.
SESB will compensate damaged electrical goods if it was caused by negligence on their part. However, consumers have to lodge a police report and provide necessary information to prove their claims.
Also present were Sabah East Coast Energy Commission Regional Director Nazlin Ab. Alim Sidiki and SESB Senior General Manager (Asset Management) Muhamad Nazri Pazil among others.