The year 2016 marked the tail-end of the rehabilitation of power plants damaged by Typhoon Yolanda (international name: Haiyan) and the subsequent companywide typhoon-proofing of all assets. Retrofitting the geothermal power plants, some of which have reached “midlife” stage, is meant to address reliability issues and results in overall enhanced reliability.
The Leyte Geothermal Business Unit (LGBU) leads the typhoon-proofing initiative by improving the resilience of its cooling towers against wind speeds of up to 300 kilometers per hour (kph). Upgrades done on the Malitbog Cooling Tower were completed in January 2016, while upgrades on the Cooling Towers of Tongonan Units 1 and 3 were completed in November and March 2016, respectively. On the other hand, the Tongonan Unit 2 Cooling Tower completed its first phase of typhoonproofing in April 2016 and expects to finish its second phase by April 2017.
Apart from the cooling towers, typhoonproofing activities are underway at the Tongonan Powerhouse and are projected to finish by July 2017. Upgrades are likewise mid-way and targeted for completion in the Upper Mahiao, Malitbog, and Mahanagdong Units A and B Powerhouses by March 2017, and the Tongonan, Mahanagdong, and Upper Mahiao Warehouses by July 2017.
Since Leyte is squarely in the midst of the typhoon belt, such upgrades are expected to address potential destruction and unexpected outages which are likely during strong typhoons.
Taking its cue from its Leyte counterpart, Negros Island Geothermal Business Unit (NIGBU) will be obtaining some of the excess spares from LGBU for its Cooling Towers as a mitigating measure in case of typhoon damage.
Moreover, the BacMan Geothermal Business Unit (BGBU) is nearly finished with its typhoon-proofing projects, which will significantly reduce BGBU’s risk of possible damage from the impact of strong typhoons. BacMan achieved its upgrades for Cawayan and Palayan Warehouses in January 2016; the Cawayan Powerhouse in May 2016; the Cawayan Control Center in June 2016; and the Palayan Powerhouse in August 2016.
Notably, the Tongonan Unit 1 rehabilitation was completed on February 4, 2017, while Units 2 and 3 are scheduled for rehabilitation in the second and third quarters of 2017, respectively. The ongoing rehabilitation of the Tongonan plant includes the retrofitting of all three (3) steam turbines, rehabilitation of all generators, installation of new transformers, and other complementary maintenance work on the rest of the plant.
The rehabilitation has gradually improved Tongonan’s reliability to 91.2 percent in 2016, a 4.3 percent increase from 2015. With higher capacity and better steam utilization, the plant’s generation is anticipated to increase in 2017.
Palinpinon will be the oldest plant in the fleet once the rehabilitation of Tongonan is completed. It is for this reason that it will undergo a Control System Integration (CSI) upgrade in the next three (3) years, starting with Palinpinon Unit 1 in 2018 and then followed by Palinpinon Unit 2 in 2019. The main objective of the CSI upgrade is to address the obsolescence of its control systems, as the same system has been in use since 1983. However, even prior to these improvements, Palinpinon I performed well year-on-year and generated a total of 937.9 gigawatt hours (GWh) in 2016, an increase of 54.0 GWh from last year.