Brownout vs blackout
A blackout is a power outage across the grid, usually more than three provinces. A brownout is strictly low voltage, but in the Philippines everybody, Meralco included, uses it for any outage.
Written for the Philippines. Brownout ang tawag ng karamihan sa pagkawala ng kuryente.
Outages come with every typhoon, so this page sits beside the typhoon guide: what to do before, during and after and the rest of the home safety section. The second half is what to do when the power is off, when the house floods, and when someone brings out a generator.
The three words
These are the definitions an NGCP officer gave at a public seminar, and how the word is used day to day.
- Blackout
- A power outage in the grid. NGCP says it usually affects more than three provinces.
- Brownout
- Strictly, low voltage: the lights dim or flicker. In everyday Philippine use it means any outage, and Meralco uses it that way too.
- Power interruption
- NGCP calls this the proper term for a loss of supply in one area. It is what most people mean when they say brownout.
Source: SunStar, quoting NGCP, NGCP conducts Power 103 seminar, 8 June 2015. Read 5 October 2026.
Source: Meralco, FAQ: Outages and Incidents. Read 5 October 2026.
Scheduled and unscheduled outages
Meralco sorts outages into two kinds. Planned ones are for maintenance, upgrading equipment, moving lines for a government project or extending service, and Meralco says customers get at least 72 hours' notice. Unplanned ones come from emergencies: not enough generation, severe weather, something touching the lines, or equipment failing.
So if you were not told in advance, it is one of the second kind, and the hazards worth reporting are the ones that come with it: a downed pole or wire, a wire that sparks, or a line that is loose or damaged.
Source: Meralco, FAQ: Outages and Incidents. Read 5 October 2026.
Yellow alert, red alert and rotational brownouts
NGCP, which runs the transmission grid, sets the alert levels under the Philippine Grid Code. The news reports them by colour.
| Alert | What it means |
|---|---|
| White alert | The normal state of the grid. Supply is enough for everyone, and reserves are there if a power plant suddenly goes offline. |
| Yellow alert | Reserve power in the grid has become low. The chance of rotational power interruptions goes up. |
| Red alert | Supply is not enough to meet demand. Widespread interruptions or rotational brownouts are expected. |
Source: GMA News, on NGCP, What does each power alert level mean?, 19 April 2026. Read 5 October 2026.
A rotational brownout is what a red alert turns into on your street. Meralco's own briefing calls it manual load dropping: it is done during a red alert, when generation is not enough or the reserve is zero, and it cuts circuits in turn so demand fits the supply. The schedule is drawn up and announced as soon as Meralco receives NGCP's forecast of the shortfall, and how long each cut lasts depends on how big the shortfall is. Residential and commercial circuits are scheduled for daytime.
If your area is on the list, treat it like any other outage: the steps below apply.
Source: Meralco, Manual Load Dropping (MLD), briefing slides. Read 5 October 2026.
What to do when the power goes off
- Keep an eye on every lit candle, and keep candles away from children and pets. The BFP suggests solar lights or lamps over frequent candle use.
- Unplug appliances you are not using. The BFP warns that plugged-in equipment can start a house fire.
- Keep the refrigerator and freezer shut. Ready.gov puts it at about four hours of cold in a closed refrigerator and about 48 hours in a full freezer.
- Charge phones, power banks and a radio while you still have power, when an outage or a typhoon is forecast. Meralco includes this in its reminders.
- Report a downed pole, a sparking or loose wire, or anything touching the lines. In Meralco areas the hotline is 16211; outside them, call your own electric cooperative or distribution utility.
Candles are the fire risk that comes with every outage. The rest of what keeps a house from catching fire is in fire safety tips for the home.
Source: GMA News, on the BFP, Fire prevention tips from BFP, 3 March 2025. Read 5 October 2026.
Source: Ready.gov (US government), Power Outages. Read 5 October 2026.
Source: Meralco, Lower Rates this September 2026, the electrical safety reminders, 11 September 2026. Read 5 October 2026.
Generators: never inside the house
The DOH's warning is plain: do not put a generator set inside the home or anywhere enclosed, because it gives off carbon monoxide that the family then breathes. Carbon monoxide has no colour and no smell. It can cause lasting harm and it can kill. The DOH issued the warning after three deaths were reported in Albay following the typhoons of late 2020.
Run a generator outside, at least 20 feet (about six metres) from the house. The US CDC adds that an open door or window does not make a garage or a room safe, and that the generator should be well away from windows, doors and vents.
The symptoms are headache, dizziness, weakness, an upset stomach, vomiting, chest pain and confusion. If anyone in the house has them while a generator is running, get everyone out into fresh air and get medical help. The numbers are on the emergency hotlines page.
Source: Philstar, quoting the DOH, DOH: Using generators indoors can kill, cause long-term damage, 16 November 2020. Read 5 October 2026.
Source: US CDC, Carbon Monoxide Poisoning Basics. Read 5 October 2026.
When the house floods
Meralco repeats these with every flood and typhoon advisory. Water and live wiring is the combination that kills, so the order matters: power off first, from a dry spot.
- Stay away from downed power lines and electrical facilities, especially any that may be damaged or under floodwater.
- If water is coming in, turn off the main power switch or circuit breaker. Your hands and feet must be dry, and you must not be standing on a wet surface.
- Unplug all appliances, turn off anything wired in permanently, and remove light bulbs if you can.
- Move electrical equipment and appliances higher if your area floods.
- After the water goes down: clean mud from electrical equipment with rubber gloves and rubber-soled shoes, make sure every wire, outlet and device is completely dry, and have a licensed electrician check the wiring and appliances before you switch back on.
- Do not turn on an appliance that has been in floodwater.
Getting the family out is covered on the flood guide. If anyone waded through floodwater, read leptospirosis after a flood.
Source: Meralco, Lower Rates this September 2026, the electrical safety reminders, 11 September 2026. Read 5 October 2026.
Source: Meralco, Typhoon Tips, electrical safety. Read 5 October 2026.
Before the next typhoon
Most long outages come with a storm. The typhoon guide covers the house, the warnings and the hours after, and the go bag holds the flashlight and radio you will want when the power goes.