Thursday’s blackout blamed on lightning

Lightning caused the massive blackout that affected the entire Cebu-Negros-Panay grid last Thursday afternoon, the National Transmission Corporation announced yesterday.

In an official statement sent to The Freeman, the state-owned transmission company blamed the power blackout on the sudden loss of power from Leyte believed to be caused by a lightning bolt that hit the Malitbog-Tabango 230-kilovolt overhead transmission cable in Leyte.

Transco explained that the lightning struck the transmission network along Malitbog to Tabango which carried the geothermal power supply from Leyte to Cebu and was then shared by the CNP grid.

At the time of the incident, it added that Leyte geothermal fields were supplying Cebu about 260-megawatts through the submarine cables that connect Tabango, Leyte to Daanbantayan, Cebu.

“The sudden cut off of the bulk of power from Leyte, in effect, resulted to the automatic protection shutdown of the Cebu Thermal Power Plant 2 (CTTP-2) and the Cebu Diesel Power Plant, which are all located in Naga City, Cebu.

Transco said that the Palinpinon Geothermal Power Plant 1 in Negros Oriental and the Panay Diesel Power Plant 1 and the three barges in Panay were also affected.

Palinpinon Geothermal Power Plant 2 was however able to maintain its operation but shifted to household only while the independent power producers isolated from the system.

Transco said power supply was gradually restored at 4:36 p.m. last Thursday when the Malitbog-Tabango line was harnessed back into operation and reenergized transmitting power up to Compostela.

With regards to the brownouts yesterday morning, Transco said that it resorted to manual load-dropping in some parts of Cebu and Panay following some technical problem in its reactor at the Tabango Cable Terminal Station in Leyte.

A reactor is a protection device that helps regulate the voltage level and prevents any abnormal voltage fluctuations.

Transco said power supply is expected to stabilize before peak hours last night after it dispatched its technical personnel to Tabango by chopper to correct the reactor problem.  -Wenna A. Berondo/BRP