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Buying tips for backup power

Choosing the generator that's right for you


There are three basic sizing requirements:

  • Continuous power or how much power is needed to run your home or chosen appliances.
  • Peak power or the highest spike of power, usually at start-up.
  • Surge current or an extra margin in case of power surges.

Decide which appliances you'll want to power and add a 10 to 20 per cent margin to your estimate for start-up and in case of surges. Automatic shut-offs will kick in if the backup system is overloaded.


  • 4 to 8 kW units can power lights and a few critical appliances.
  • 10 to 15 kW (most common for residential use) can power most home appliances, including large appliances like water heaters.
  • 20+ kW powers a household as if there was never a power interruption (if you have a natural gas water heater, you will continue to have hot water during a power outage).

Use the Generator Sizing Guide to decide the right amount of backup power for your home

Your local retailer can you help find a model, once you decide on the important power needs in your home during an emergency, and how common and long-lasting your outages may be.


Pricing depends on the size of the model and whether you want a home or portable model.

For example, home generators on average can cost $3,000 for the 6 to 8 kW models, while models with 11 to 20 kW cost between $5,000 and $10,000.

Remember to budget the costs of installing the concrete pad, wiring and gas line. Depending on the size of the unit, installation costs can range from $800 up to $2,500.

Other features

Useful features that will make your generator easier to use and longer lasting:

  • an LED panel that lets you know the status of the generator, or if the start fails
  • a "self-diagnostic" feature, which will alert you to any problems
  • a "self-maintenance" feature that (without transferring power) runs for a few minutes on a schedule to circulate oil and recharge the battery
  • a voltage regulator, which deals with surges that could damage electronics such as computers.

Other considerations

  • manufacturer's warranty - it's different for each model, but 2 to 5 years is average
  • annual service options for changing the oil and air filter, checking the battery and testing the system
  • your gas pressure or psi - if it is too low for the generator you choose, your model may not function, especially at peak power. Contact a licensed gas contractor for help.  Contact FortisBC for higher delivery pressures.

 Choose the right model


Make sure that the model you are choosing will work with your gas pressure or psi. If it is too low, your model may not function, especially at peak power. Contact FortisBC if you require higher delivery pressures.




Connecting to natural gas means unlimited fuel, but some engines should be shut down after 50 to 100 hours of operation to change the motor oil. If you have a portable generator for household appliances, you might want a separate uninterrupted power supply for sensitive things like computer equipment.