A

power transformer at the Tello steam power plant in Makassar, South Sulawesi, blew up and caught fire at around 11 p.m. local time on Wednesday, causing a major blackout and leaving 90 percent of the province in complete darkness.

As of Thursday noon, several regions in South Sulawesi, including a number of places in Makassar, were still affected by the blackout.

State power company PT PLN overseeing South Sulawesi, West Sulawesi and Southeast Sulawesi (Sultanbatara), continues efforts to restore the power network.

PT PLN Sultanbatara region general manager Zulkifli Abdullah Pute on Thursday said his office was still addressing the situation.

“We are making efforts to restore 100 percent of the outage. Power will soon be restored to the entire area of South Sulawesi and West Sulawesi,” he said.

The damaged transformer functioned as a power stabilizer, but it was on standby because the diesel-powered generator connected to it was no longer operating.

Despite that, the 12.5 megavolt capacity transformer was included in the South Sulawesi and West Sulawesi interconnection power system.

“The transformer was on standby but was still linked to the South Sulawesi and West Sulawesi power network. When the whole system was affected this automatically led to the power outage in almost every region in both provinces,” said Zulkifli.

The South Sulawesi and West Sulawesi PLN office was only able to restore power over three hours later and only to a number of areas in Makassar.

“We are carrying out the repair work in stages because the power plants linked to the interconnection system are also linked to the system,” he added.

The slowest power plant to connect to the system is the Jeneponto steam power plant (PLTU), despite the fact that it supplies the biggest power output in the area. The coal-fired PLTU has two generators, each with a capacity of 200 megawatts (MW).

PT PLN Sultanbatara legal and communications manager Mohammad Yamin Loleh said despite the damaged transformer, the power network in both provinces would not be disrupted.

He argued that PLN was equipped with a reserve power of around 60 MW, while the inoperative generator, due to the damaged transformer, only had an output of 8 MW.

Currently, the capacity linked to the interconnection system in South Sulawesi and West Sulawesi is 784 MW, while the peak load is 724 MW.

“Actually, the installed capacity has reached 900 MW, however, as a number of power generators are undergoing maintenance, our output has dropped to 784 MW. God willing, the damaged transformer will not have an impact on the power supply and we can avoid the rotating blackouts,” said Yamin.

Yamin told reporters that he was not yet aware of the cause of damage to the transformer, which was made in 1988. A PLN investigative team along with the police are continuing to investigate the case.

“The cause of damage is still being probed,” he said.

Residents living around the Tello PLTU were stunned by the explosion, which was followed by a fire and power outage. The fire was extinguished an hour later after dozens of fire engines arrived at the scene.