Meralco concerned over yellow-alert status of Luzon grid

By Lenie Lectura - September 20, 2017

https://businessmirror.com.ph/meralco-concerned-over-yellow-alert-status-of-luzon-grid/

THE Manila Electric Co. (Meralco) expressed concern over the frequent number of times the Luzon grid was placed on yellow alert.

A yellow alert is issued when the contingency reserve is less than the capacity of the largest synchronized unit of the grid. In Luzon this is equivalent to 647 megawatts (MW), or one unit of the Sual power plant in Pangasinan.

The Luzon grid was placed on yellow alert by the National Grid Corp. of the Philippines (NGCP) on August 30, September 9 and September 16.

Fernandez said the yellow alerts were triggered by forced outages of several large power-generation facilities.  In turn, these triggered the Automatic Load Dropping (ALD) scheme of Meralco.  This meant certain areas in Meralco experienced momentary interruptions to help the grid recover from the generation outages.

“A yellow alert means there were not enough reserves to cover the largest-running generating unit at the time,” Fernandez said. “We are concerned. Since August 30, there has been a once-a-week incidence of yellow alert. Our concern is that while it has not led to red alerts, automatic load dropping occurs when power plants trip. This means some of the customers lose electric service because of the tripping of some power plants,” the Meralco official said.

Meralco’s Interruptible Load Program (ILP) participants were also advised to prepare for possible deloading, in case the situation deteriorates.  In the end, the ILP did not need to be activated in the three instances.

Fernandez commented the yellow alerts and the triggering of the ALD mechanism signal the need for additional capacity in the Luzon grid.

“We need new capacities,” he said, pointing out that, as demand for power continues to increase, additional generation supply will be needed, both to meet new demand and to improve the reliability of the electric system.

“While new capacity had been coming in since 2016, demand has also been growing.  In the Meralco area alone, electricity consumption had grown almost 4 percent to date.  This despite having registered a robust growth of 8.1 percent in 2016 due to the effects of El Niño and elections-related spending,” the Meralco official said.