(Coconuts Manila) Today, June 2, areas around Metro Manila have been put on Yellow and Red Alert levels by Meralco—which, in other words, may mean rotational power outages in certain neighborhoods.

The cause, quite simply, is that there isn’t enough power to meet demand, explains Meralco in a fact sheet the power company published on their website.

When this happens, the National Power Grid Corporation of the Philippines puts out a Red Alert notice on the Luzon power grid. Rotational brownouts — also known technically as Manual Load Dropping — are implemented to maintain the integrity of the power system. In other words, electricity is cut off in certain areas of the power grid to prevent the whole thing from collapsing.

Why the shortfall is happening now is due to a number of different factors coming into play at the same time. Obviously, summer is peak electricity usage season for Filipinos, because everyone’s using airconditioners and other cooling devices.

There are also unplanned outages at one or more of the 137 power plants that currently supply electricity to the Luzon grid. Additionally, more than half of these power plants are over 15 years old.

And so why doesn’t Meralco just build more power plants? “For now, we continue to work with the rest of the energy industry in order to manage the challenged power supply situation right now. This is a long-standing issue that needs the government and the power industry to work together,” the explainer diplomatically goes on to say. “There are Power Supply Agreements (PSAs) pending with the Energy Regulatory Commission (ERC) which, if approved, will mean more power plants being built and additional capacity to the grid.”