What to Know When the Power Goes Out

How to Prepare for Winter Blackouts

A loss of power due to winter storms can be devastating. Understanding blackouts, being prepared, and knowing how to respond can help protect your family and home when the power goes out.

During the wintertime, homeowners can find themselves in the dark not just because of earlier sunsets, but also because of blackouts and power outages. With unpredictable winter weather on its way, homeowners need to understand what causes these losses of power and how to prepare for and respond to them.

The How & Why of Blackouts and Power Outages

Power outages can have a variety of causes, and depending on the reason, can last from a few minutes to more than a week. There are also differences between a standard “power outage” and what is known as “rolling blackouts.” A good understanding of the situation is important in order for a homeowner to respond appropriately.

A power outage is usually caused by damage to some part of the power grid.

What’s included in a power grid?

  • Power generation (eg: the power plants).
  • High voltage transmission lines.
  • Substations.
  • Lines that deliver power to end-users.

Damage to any part of this system can cause a loss of power for businesses and residences that rely on the grid for service. For instance, damage to a power plant or a substation could cause a significantly long outage, whereas damage to a residential power line may be easier to repair and cause only a few hours or days of outage.

As opposed to power outages, which can be caused by damage, short circuits, or other unexpected events, a “rolling blackout” is an outage that is intentionally caused and managed by the power company. Sections of the power grid are cut off from service periodically to reduce demand on the grid and prevent it from being completely overloaded. If demand on the power grid overloads the system’s capacity, it could lead to serious damage to equipment and power lines, leading to longer and more significant losses of power.

The duration of rolling blackouts depends on the severity of the situation that necessitated them. A long period of extreme cold may require longer rolling blackouts to protect the power grid. In rolling blackouts, electric service is often prioritized for key locations such as hospitals.

Example: The 2003 Northeast Blackout

In August of 2003, a combination of transmission line failures and a massive power surge led to a significant blackout, leaving large areas of the northeast United States and Ontario without power. In all, 10 million customers in Ontario lost electric service during the blackout. The chain of events that caused the blackout led to an overall decrease in available power through the grid as power plants were brought back online and transmission lines were repaired. During this time, provincial officials warned that rolling blackouts may be necessary to reduce demand while repairs were conducted. Ultimately, power was restored without rolling blackouts becoming necessary.

Dangers of Power Outages

If a home relies on an electric HVAC and/or water heater system, a loss of power means a loss of heat. Low temperatures can cause the water in pipes to freeze and expand, putting stress on the plumbing joints and the pipes themselves. These areas include the following.

  • Sinks.
  • Showers.
  • Toilets.
  • Sprinklers.
  • Radiant heating systems.
  • Other systems containing water.

Freezing can cause them to burst, leading to water flowing into kitchens, bathrooms, basements, and walls. If not addressed quickly, this water can cause mould issues down the line.

Sump Pumps

Water damage can also occur because of the loss of power to systems like sump pumps. In houses with basements, a sump pump works to collect and divert water away from the foundation of the house. Without power, this usually diverted water can infiltrate basements and cause damage.

Dangerous Alternative Heat Sources

Desperate homeowners who would usually rely on electric HVAC systems will sometimes turn to alternative heat sources, such as propane or charcoal grills, or use generators to provide emergency electricity. These items are designed for outdoor use only and can lead to fires or carbon monoxide poisoning because of improper use.

Power Outages and Home Appliance Care

Other electronic devices and appliances in the home may be damaged as a result of a power outage. When power is restored, it can cause a surge of electricity, which can damage things like tools, appliances, and electronic equipment. To protect these electronics, GetPrepared.ca recommends they be turned on/off or unplugged during a power outage. The surge of electricity can also trip circuit breakers within the home, so it is smart to check the electrical panel once power is restored.

Without power, refrigerators and freezers cannot keep food cold indefinitely. Not only can this cause food to spoil and lead to expenses to replace the contents of these appliances, but it could also put families at risk of illness from consuming spoiled food.

How to Prepare for Power Outages

If the forecast calls for severe winter weather, or if the power company says that rolling blackouts may be imminent, there are important steps to take to prepare for potential power outages.

Turn Up The Thermostat

A couple of days before the arrival of cold weather, turn the home’s thermostat up a couple of degrees. This will help keep the home warmer longer, putting off the need for alternative heating sources and reducing the risk of frozen pipes.

Freeze Water Jugs in The Freezer

If possible, fill milk jugs or other containers with water and freeze them. The fuller a freezer is, the better it will be able to maintain its temperature without power.

Charge Electronic Devices

Charge cell phones and other electronic devices needed for communication. During a power outage, homes without functioning landlines may be cut off from communication without charged cell phones. Consider purchasing and charging a portable charger power bank as well, in case of a prolonged outage.

Test Detectors and Alarms

Test smoke alarms and carbon monoxide detectors. The use of generators and alternative heating methods can increase the risk of fires and carbon monoxide poisoning. Functioning smoke alarms and carbon monoxide detectors on each floor can provide an early alert to these potential dangers.

Identify and Address All Potential Medical Needs

Identify medical needs and have a plan for addressing them. Some individuals may rely on electricity for assistive devices such as supplemental oxygen delivery systems and CPAP machines. Others may require medications that must remain refrigerated, such as insulin. These individuals can contact their power company to let them know of their medical need, which can be noted on their accounts. In power outage situations, these customers may receive regular updates from the power company or be designated as a priority customer for the restoration of power.

Backup Power

Have battery backups or a generator to provide power for essential items like sump pumps, refrigerators, and medical devices. A battery backup on a home’s sump pump system can mean the difference between a wet or dry basement in the event of a power outage.

Build an Emergency Kit

Have an emergency kit. An emergency kit can help keep a family safe in severe weather. Among other things, GetPrepared.ca suggests the following items be included in a home emergency kit – water, food, a wind-up or battery-operated radio, flashlights, and a first aid kit.

Have an Emergency Contact List

Keep a list of phone numbers and resources handy in case of an outage. This should include the power company, emergency services, local contractors (electricians, plumbers, arborists, etc.), and a restoration company to assist in case of damage.

When the Lights Go Out

So what is a homeowner to do when the power goes out? Responding quickly can make a big difference.

If possible, report the outage to the power company. This provides the power company with essential information about where service needs to be restored. Power companies will often provide an option to opt-in for updates about the outage and projected times for the restoration of service.

Keep Freezers and Refrigerators Closed

According to Ready.gov, a refrigerator without power will keep food cold for approximately 4 hours, and a full freezer will maintain its temperature for approximately 48 hours. In any case, the best approach to avoid foodborne illness after a power outage is “when in doubt, throw it out.”

Keep a Close Eye on Pipes

Open cabinet doors below kitchen and bathroom sinks to let warmer air reach pipes and help prevent them from freezing. Opening cold water faucets to allow a small trickle of water will keep water moving in pipes and help reduce freezing risk. Be aware that if temperatures drop too low and pipes freeze and burst, it may not be evident until they warm and water begins flowing again.

Unplug Electronic Devices and Appliances

Protect electronics from power surge damage by unplugging them once the power goes out and waiting to plug them back in until after power has been restored.

Learn About Warming Centers

Check local government sites to determine if “warming centers” are available. These are temporary shelters for individuals without access to heat, providing an escape from the bitter cold that can come with a winter power outage.

Worst Case Scenario

If a home sustains damage due to a power outage, whether from frozen pipes, electrical issues, smoke, or fire, the best approach is to call a trusted disaster recovery partner like First Onsite to navigate the recovery process.


Public Safety & Emergency Preparedness Canada – Ontario–U.S. Power Outage—Impacts on Critical Infrastructure: http://cip.management.dal.ca/publications/Ontario%20-%20US%20Power%20Outage%20-%20Impacts%20on%20Critical%20Infrastructure.pdf

GetPrepared.ca – During a power outage: https://www.getprepared.gc.ca/cnt/hzd/pwrtgs-drng-en.aspx

GetPrepared.ca – Get an emergency kit!: https://www.getprepared.gc.ca/cnt/kts/bsc-kt-en.aspx

Learn more about protecting your property from winter weather damages by downloading our Winter Weather Guide and Checklist.

Sign up for Updates