Power outages: Causes, preparation, and what to do during and after

Updated September 11, 2023

We’ve all been there. You’re watching your favourite show, cooking dinner or cheering on your team during the big game and all of a sudden: the power goes out!

Besides being annoying and disruptive, power outages pose health and security risks, especially during extreme weather events. While most power outages don’t last long, some can last for days. Read on to learn about the causes of power outages, what you can do to prepare for them, and what to do during and after a power failure.

Hydro technician repairing lines

What are the causes of power outages?

There are two types of power outage: planned and unplanned. Planned outages are scheduled by your electricity company to maintain the network and to protect their workers while they perform their duties, such as cutting tree branches near a hydro pole. Clients are advised of these planned outages.

The majority of power outages are unplanned. Here are some of their causes:

  • Extreme weather events (thunderstorms, ice storms, floods, earthquakes, tornadoes)
  • Accidents (a driver crashing into, or a tree falling onto, a telephone pole)
  • Animals (a squirrel or a raccoon chewing through a cable)
  • High usage (overloaded electricity grid due to higher than normal usage)

Preparing for a power outage

Emergency candles burning in the dark

Since power outages can occur at any time, it is important you be prepared for such an event. You should always have the following items close at hand:

  • A flashlight and batteries
  • A battery-powered radio
  • Candles
  • A fondue burner and fuel
  • A lighter and/or matches
  • Warm blankets
  • A supply of wood if you have a wood-burning stove or fireplace

If you use a combustion heating system in your home, such as a gas or wood fireplace, make sure to install a functioning carbon monoxide detector and learn how to recognize the symptoms of carbon monoxide poisoning.

What to do during a power outage

Your electricity company will provide updates on the status of the outage. You can keep abreast of the situation by either calling the company, checking their website or by listening for the latest news on a battery-powered radio.

Avoid constantly opening the fridge or freezer in order to preserve your food as long as possible. If you have vulnerable neighbours, check on their status to see if they need any help.

Do not use items like a charcoal or propane barbecue indoors. In addition to causing a fire risk, these items release carbon monoxide—an odourless, colourless gas that can cause sickness and death. If you are using candles for lighting, do so safely as they can be a fire risk.

If the outage is expected to last several days, you may need to leave your home, especially during the winter months. If you do not have a place to stay, your municipality will provide you with information about temporary shelters. Before you leave, turn off the main power breaker and backup heating system if you have one. In addition, close the main water valve and drain the pipes. Pour antifreeze into the toilet tanks and bowls and into all the sink drains.

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What to do after a power outage

When power is restored, everything that was on when the power outage occurred will turn back on, so make sure to check for lights, appliances or electronics that don’t need to be on to avoid wasting electricity or a power surge. Remember, these devices consume energy, even when they are off.

Reset any electric clocks to the correct time. If the power outage was of short duration, the food in your fridge or freezer should be alright, but check for any signs of deterioration. As well, do not take any medication that must be stored in a cool place.

If you had to leave your home during the outage, it is better to return during the day when it is easier to spot any damage or hazards. Make sure the water heater is full before turning on the power.

After turning on the main power breaker, turn on your electrical appliances one by one. Open the main water valve and taps. If you use gas heating, have a specialist turn it back on. You will have to throw away any perishable food in the fridge or freezer.

Power outages and home insurance

Power outages don’t typically damage your home, but there is one thing to be aware of when it comes to home insurance: spoiled food.

If the power is out for an extended period of time (24-48 hours), the food in your refrigerator and freezer may start to go south. If it reaches the point that you need to throw it out, your home insurance may actually cover the cost of replacing it. After all, the cost of all that food can add up quickly.

The exact coverage for spoiled food varies from insurer to insurer. Often, policies offer only limited coverage for spoiled food (up to $500 or $1,000, for example). The coverage also depends on what caused the outage. Your spoiled food might be covered if a storm cut your power, but probably wouldn’t be covered if the power’s out because you didn’t pay your hydro bill.

Commonly asked questions

Can power outages damage electrical appliances?

Repeated power outages can damage electronic devices and appliances like TVs, computers and washing machines. Fortunately, there are a few steps you can take to prolong the life of these devices and lower your electricity bill:

  • Regularly unplug electronics when you are not using them, especially when you are away from home.
  • After a power outage, turn these devices back on gradually and not all at once to avoid a power surge.
  • Avoid connecting multiple devices to the same circuit or plug.
  • Connect your devices to a surge protector.

How long is the power usually out?

Most power outages are short in duration, especially planned outages. However, some outages can last for several hours or even days depending on the severity of the event. You can contact your electricity provider to find out the status of the outage and the estimated time of reconnection.

How come the houses in other parts of the neighbourhood still have power and we don’t?

A single street may be served by two different distribution lines, circuits, or substations. It is possible that the circuits serving the houses across the road did not sustain any damage.

Want to learn more? Visit our Home and Personal Safety resource centre to find more information about protecting your family and your home. Or, get an online quote in under 5 minutes and find out how affordable personalized home insurance can be.


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