MANILA, Philippines — Rotational blackouts may persist in the Luzon grid this week as large power plants have extended their unplanned outage and warmer temperature cripples supply in the power grid.
The National Grid Corp. of the Philippines (NGCP) raised the red alert warning on the Luzon power grid from 2 p.m. to 4 p.m. yesterday. Yellow alert notice, on the other hand, was up from 11 a.m. to 2 p.m. and 4 p.m. to 5 p.m.
In another advisory later in the day, the NGCP said the red alert was bumped up from 1 p.m. to 3 p.m.
A yellow alert means there were not enough reserves to cover the largest running generating unit at the time but does not necessarily lead to power outages. A red alert means there is severe power deficiency which could lead to rotational power interruptions.
NGCP said available capacity was at 11,729 megawatts while peak demand was projected to reach 11,514 MW.
In a text message yesterday, Energy Secretary Alfonso Cusi said supply was severely affected by several power plants on outage.
“The DOE is verifying the causes of today’s issuance of yellow and red alerts by NGCP. Although the demand is well within the forecasted levels, there is an observed sudden drop in the available generation capacity. If the red alert is not lifted, there is a possibility of rotational outages,” he said.
Based on data from the DOE, the forecast peak demand for this year is 11,840 MW.
“We haven’t really hit our demand forecast yet. The highest for the year, which was achieved last Friday, was at 11,640 MW,” Energy Assistant Secretary Redentor Delola said in a briefing.
However, developments over the weekend triggered the yellow and red alerts in the power grid, DOE officials said.
“Over the weekend, we registered higher index. For every degree index increase in temperature, there is an equivalent 100 MW increase in demand,” DOE-Electric Power Industry Management Bureau (EPIMB) director Mario Marasigan said.
Over the weekend, several areas in the Philippines registered heat indices of 41 degrees Celsius and higher, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said.
The heat index is the apparent temperature or what people feel as the temperature affecting their body, according to the weather bureau.
“We’re recording the heat index. That’s what drives our consumers to use cooling equipment,” Delola said.
Aside from the intensifying heat, several power plants proceeded with their scheduled maintenance, some remained on extend forced outage while other plants are running on derated capacity, with the Luzon grid losing 3,771 MW Monday.
Data from the DOE showed 435 MW were from hydropower plants which went on planned outage on May 30.
Marasigan said the 647-MW Sual unit 2, the 345-MW GNPower Mariveles and the 300-MW Sem Calaca unit 2 are on extended, unplanned outage while the Ilijan gas-fired power plant is generating only 716 MW from its total nameplate capacity of 1,200 MW due to limited gas supply from the Malampaya project, which is experiencing output restriction.
The DOE was banking on the first unit of GNPower Dinginin (GNPD) coal plant to bump up reserves, but the generating company cancelled its commissioning activities due to suspected boiler tube leak that needs to be addressed, Delola said.
“GNPD is still under testing and commissioning. It’s not yet stable but we are really banking on this,” he said. “There’s a possibility this yellow and red alert will last for a couple of days.”
With severely low reserves, NGCP implemented manual load dropping (MLD) to maintain a balanced system in parts of Isabela, the entire province of Quirino, Olongapo City, parts of Quezon province, parts of Camarines Sur, parts of Ilocos Norte, parts of La Union, Zambales, Albay and Metro Manila between 1 p.m. to 3 p.m.
Supply deficiency
Meanwhile, the Manila Electric Co. experienced supply deficiency of 163 MW and 95 MW from 1 p.m. to 2 p.m. and 2 p.m. to 3 p.m., respectively, leading to MLD within its franchise area, Meralco vice president for corporate communications Joe Zaldarriaga said in a text message.
To address the high system demand in the Luzon grid and the increased ambient temperature because of the summer season, Meralco called out its interruptible load program (ILP) participants to voluntarily deload from the grid during the red alert.
It said 86 participating establishments have confirmed willingness to deload under ILP, equivalent to a capacity of 168 MW.
In case of supply deficiency, corporations and commercial establishments participating under the ILP are ready to use their generator sets to help prevent/minimize incidents of power outage, Meralco said.
As the country undertakes vaccination programs, the DOE reminded vaccine facilities and distribution utilities (DUs) to ensure triple backup to protect COVID vaccines.
“They should have their gensets all ready. We also call on our partner facilities to have that triple backup system. As of now, we have red alerts, DUs and those facilities should have backup gensets and should inform DOE... so that we can accordingly respond,” DOE Undersecretary Felix William Fuentebella said.
The DOE said it continues to monitor the power situation and will submit additional information for consumers and enforcement agencies, including the Energy Regulatory Commission, Philippine Competition Commission and Department of Justice, considering its long-term strategy of addressing the power supply and demand situation during the summer.
It also reminded distribution utilities and system operators of contracting obligations to address the needed capacity increases for a reliable power system for consumers.