Repair of Leyte transmission lines stepped up

MANILA, Philippines - Transmission lines in Leyte, Cebu and Samar may soon be operational again as the National Grid Corp. of the Philippines (NGCP) speeds up repairs.

However, the source of electricity for the three provinces will remain problematic due to the forced shutdown of the 650-megawatt Unified Leyte power plants, the country’s energy chief said yesterday.

Energy Secretary Carlos Jericho Petilla said that while the damaged caused by Super Typhoon Yolanda on the geothermal plant operated by Energy Development Corp. (EDC) will not cripple electricity supply in Luzon, it would continue to affect the typhoon-hit provinces.

“It will not cripple supply in Luzon but it will affect supply in Leyte, Samar and Cebu,” Petilla said.

The EDC said it is not yet clear when it would be able to conclude the repairs but stressed it was exerting all efforts to put the power plants back to service.

Petilla said the target is to restore electricity in the affected areas by Dec. 24. 

Yolanda ripped through Central Visayas last Nov. 8, damaging critical facilities in the power plants.

“None of the main power plants constituting the 650 MW are currently operable,” the EDC said in a disclosure to the Philippine Stock Exchange (PSE) last week.

The Unified Leyte plants consist of the 130-megawatt Upper Mahiao, 232-MW Malitbog, 180-MW Mahanagdong and 112.5-Tongonan power plants.

According to an article in The New York Times, the power plants essentially rely on two steps: first they spin turbines using the tendency of water at such high temperatures to expand into steam, and then they spin further turbines as the steam cools.

“Those four power plants were designed to condense the steam into water in steel-reinforced wooden cooling towers for reinjection into the ground,” the article said.

The EDC said Yolanda destroyed all four cooling towers.

Leonita Sabando, environmental management chief at the site, told the New York Times  that the EDC is studying whether to replace the cooling towers with identical construction or build new ones that may be more durable.

In its disclosure last week, the EDC said the cooling towers of the Malitbog, Tongonan and Mahanagdong power plants are not working due to significant damage sustained.

In addition, part of the cooling system of Upper Mahiao plant was also damaged, the EDC said.

The control systems of Tongonan, Mahanagdong and Upper Mahiao also sustained water damage.

Furthermore, the EDC said that the small optimization plants consisting of 15 MW Tongonan Topping Cycle and the 16 MW Malitbog Bottoming Cycle are being assessed.

The steam field lines, on the other hand, appear to be operable despite manifest damage sustained, the EDC said but quickly added that the company’s buildings, offices, warehouses, laboratories, and staff housing facilities have sustained varying degrees of damage.

With this, the EDC has formally written the National Power Corp. (Napocor) regarding the force majeure provisions of its power purchase agreement.

This developed as the NGCP reported that it has energized two vital lines in Leyte and Iloilo on Friday.

“At about 8 p.m., lights were turned on for the first time at the Ormoc City Hall in Leyte two weeks after Typhoon Yolanda badly hit the area, renewing Leytenos’ hopes for a bright Christmas as they start to rebuild their lives after the typhoon,” the NGCP said.