NGCP issues yellow alert in Visayas

The National Grid Corp. of the Philippines placed the Visayas grid under yellow alert on Monday afternoon after forced outages and derated power plants reduced available reserves. NGCP said the alert would cover the 2 p.m. to 4 p.m. trading interval on May 18, with available capacity at 2,676 megawatts against projected peak demand of 2,513 MW. The company said 852.9 MW was unavailable because of forced outages, while another 246.8 MW was running on derated or limited capacity. The move came after several days of strained grid conditions in Luzon and the Visayas, with utilities in some areas already carrying out rotational brownouts. ### Which plants were cited in the latest Visayas alert? NGCP identified Therma Visayas Inc. Units 1 and 2 and Panay Energy Development Corp. Unit 3 among the large units on forced outage in the Visayas, according to local reports citing the grid operator’s advisory. The same reports said the unavailable capacity from outages and derates was enough to tighten operating margins during the afternoon peak. (gmanetwork.com) The Department of Energy said on May 12 that Energy Secretary Sharon Garin had directed Therma Visayas Units 1 and 2 and Panay Energy Development Corp. Unit 3, along with other stakeholders, to restore affected plants after an earlier Visayas yellow alert. The department said that alert on May 12 ran from 5 p.m. to 8 p.m. (tnt.abante.com.ph) ### What does a yellow alert mean for consumers and utilities? NGCP said in an earlier explanation that a yellow alert is issued when operating margin is insufficient to meet the contingency requirement, leaving the grid at risk if another major unit trips. The company distinguishes that from a red alert, which means supply is insufficient to meet both demand and the required reserve. Gulf News reported that rotational brownouts hit parts of Luzon as reserves thinned and several large generating units and transmission lines went offline. (doe.gov.ph) The report said utilities were cutting load in rotating blocks to keep system frequency stable and avoid a wider collapse. (ngcp.ph) ### Why were Luzon and Visayas both under pressure this week? The Department of Energy said on May 14 that it and the Energy Regulatory Commission had directed NGCP to submit a full incident report on the yellow and red alerts affecting the Luzon and Visayas grids. The department said the Grid Reliability and Technical Force, or GRTF, would conduct a technical assessment with the ERC, the Independent Electricity Market Operator of the Philippines, TransCo and PSALM. (gulfnews.com) Energy Secretary Sharon Garin said on May 13 that NGCP had been directed to immediately resolve transmission constraints affecting dispatch of large power plants and triggering yellow and red alerts in the Luzon grid. The DOE said major disruptions involving key facilities could have broader implications for power flows and supply conditions in both Luzon and Visayas. (doe.gov.ph) ### How tight were the margins in the Visayas on May 18? The most telling number in NGCP’s Monday advisory was the gap between available capacity of 2,676 MW and projected peak demand of 2,513 MW. That left only 163 MW before accounting for contingency requirements, a narrow cushion in a grid already carrying hundreds of megawatts of forced outages and derates. That arithmetic is an inference based on NGCP’s published capacity and demand figures. (doe.gov.ph) Cebu Daily News reported that the Visayas grid was again being placed under yellow alert on May 18 as multiple plant outages continued to strain supply. Manila Standard said millions of consumers in Luzon and the Visayas had already endured a third straight day of rotating brownouts by Friday as outages, transmission problems and high demand weighed on the system. (gmanetwork.com) ### What happens next in the government response? The Department of Energy said NGCP must submit a comprehensive incident report covering the recent Luzon and Visayas alerts, including operational data, incident reports and technical findings. The agency said the GRTF assessment will examine the circumstances surrounding the disturbances and establish root causes. (cebudailynews.inquirer.net) NGCP’s next public updates are likely to appear on its advisories and media pages, while DOE statements are being posted through the department’s press-release pages. As of May 18, the latest verified official actions were the Visayas yellow alert for Monday afternoon and the DOE’s standing directives for incident reporting and plant restoration. (ngcp.ph) (doe.gov.ph)