MANILA - The Luzon grid was placed on "yellow alert" on Tuesday, the National Grid Corporation of the Philippines (NGCP) said.

NGCP said the alert was raised due to "lower level contingency reserves brought about by insufficient power supply."

As of 10:30 a.m., the available capacity in Luzon was at 10,170 megawatts, and peak demand was at 8,958 megawatts.

Meanwhile, the Manila Electric Co. (Meralco) advised its customers that energy efficiency during a yellow alert will help prevent brownouts.

Meralco said to conserve energy, air conditioners should be set to 25 degrees Celsius and appliances should be unplugged when not in use. -- Report from Alvin Elchico, ABS-CBN News