Once in a while, you may encounter news on your timeline about a “yellow alert” or “red alert”, perhaps shared by your local electric company. What do these power advisories really mean, and what do they have to do with the brownouts happening in your area?

What do the red and yellow alerts mean?

Power advisories are released by the National Grid Corporation of the Philippines (NGCP) to inform citizens about the power supply’s current condition in a certain grid. Normally, the grid is on white alert, which means that there is a sufficient power supply. When a yellow alert is issued, this means that there is a lower power supply than usual due to thinning reserves.

When conditions worsen, a red alert is issued, which means that there is a significantly low and insufficient power supply that may not be able to meet the demand in the grid. When this happens, rotational brownouts or manual load dropping may occur in the affected areas, although not guaranteed.

What causes the thinning power supply?

According to the NGCP, a decrease in power reserves is often caused by technical problems in certain power plants, leading to unplanned or forced outages. These problems are especially common in older power plants, which malfunction frequently. 


De-rating (reducing operations) and scheduled preventive maintenance of certain power plants also lead to thinner power reserves. When the plants return to regular operations, the yellow or red alerts are lifted accordingly and return to a white alert.

When do brownouts usually occur?

Brownouts occur sporadically throughout the year, whenever there is a significant decrease in power supply due to problems in power plants. They can also occur when the power supply can not sufficiently support the increase in demand.

This is most noticeable during hot days when demand often catapults because people use more electricity to stay cool. Thus, brownouts and power advisories like red and yellow alerts become more common during the months of March to June, which tend to be the hottest months in the Philippines.

Additionally, demand is higher during school breaks and holiday seasons when families are inside the household more often and use more electricity, increasing the likelihood of power shortages.

What is being done to avoid power shortages?

While power supply usually varies throughout the year, some consumers have raised concerns due to increasingly frequent yellow and red alerts issued in the Luzon grid, the country’s largest power grid. As a consequence, rotational brownouts become more frequent across Luzon, including Metro Manila.

The Department of Energy (DoE) has shared some of the short-term and long-term measures that it is taking to mitigate the issue of increasing power shortages.

During brownouts, the DoE implements the Interruptible Load Program (ILP), which implores big businesses with generation capacities to open their generators when a red alert is issued by the NGCP. This helps mitigate the power deficit and decrease the possibility of rotational brownouts in the area.

For more long-term solutions, the DoE and the Energy Regulatory Commission (ERC) have projects in the pipeline to build more power plants to increase overall energy generation in the future. A transition to renewable energy sources is also being considered.


Another goal is to link the country’s three grids — in Luzon, Visayas, and Mindanao — and create one unified grid. This will ensure that the energy sources can be shared across the network in case a grid is currently experiencing a power shortage. The Mindanao-Visayas Interconnection Project (MVIP) launched in 2018 works to achieve this goal by linking the Mindanao grid to the already-connected Luzon and Visayas grids.

What can I do to help avoid power shortages?

Ordinary citizens are also being encouraged by the DoE and NGCP to do their part in conserving energy in order to help mitigate the power deficit. Individuals and families are advised to be more energy-efficient in the household, especially when using energy-consuming appliances like refrigerators and air conditioners.

Households should also consider looking into renewable sources like solar energy. Switching to a solar energy system helps offload the demand from the power grid, and can also significantly lower your monthly electricity bills. Some solar energy systems are also off-grid, so they are self-reliant and can supply electricity to the household even during power outages. This can mean saying goodbye to brownouts altogether.

It pays to understand what the common power advisories like yellow and red alerts mean, so that you know what to expect whenever one is issued or shared by your local electric company. When you see a red alert, now you know that a brownout is possible in your area, and you can prepare beforehand.

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