Should I get a 16kW or 22kW generator for my Toronto home?

The right size depends entirely on your home's electrical load, and for most GTA homes, the answer comes down to whether you want to power essential circuits or your entire house — a 16kW unit handles essentials plus comfort loads in a typical 1,500 to 2,000 square foot home, while a 22kW unit can power virtually everything in homes up to 3,000 square feet. Your electrician will perform a detailed load calculation to determine the exact requirement, but here is how to think about sizing.

A 16kW standby generator produces roughly 66 amps at 240 volts. This is enough to simultaneously power your gas furnace blower (5 to 10 amps), refrigerator (3 to 5 amps), sump pump (8 to 12 amps starting surge), 20 to 30 LED light fixtures (negligible draw), a well pump if applicable, garage door opener, security system, internet router, and several convenience outlets for charging devices. For a typical GTA home with a gas furnace, gas water heater, and gas stove, a 16kW unit comfortably covers all your actual needs during an outage. The unit costs approximately $4,000 to $6,000 for the generator alone, or $8,000 to $12,000 fully installed with ATS, concrete pad, gas line, and permits.

A 22kW standby generator produces roughly 91 amps at 240 volts. You need this larger unit if your home has electric-heavy loads such as an electric water heater (18 to 25 amps), electric range or oven (40 to 50 amps), central air conditioning (20 to 40 amps), a Level 2 EV charger (32 to 50 amps), electric baseboard heaters in multiple rooms, or a hot tub (40 to 50 amps). If you have several of these loads and want to maintain full normal operation during an outage — not just essentials — the 22kW is the appropriate choice. Installed cost runs $10,000 to $15,000 in the GTA market.

The critical factor your electrician will assess is your panel's total connected load versus the generator's continuous output. A 200-amp panel does not mean your home draws 200 amps continuously — most GTA homes have a peak demand of 60 to 120 amps depending on what is running simultaneously. The load calculation considers the running wattage and starting surge of every circuit. Air conditioners and well pumps have starting surges 3 to 4 times their running draw, which must be within the generator's surge capacity.

For the GTA housing stock specifically, here are general guidelines. Post-war bungalows and side-splits in Scarborough, Etobicoke, and North York with gas heating and gas hot water typically do well with 16kW. Larger two-storey homes in Vaughan, Richmond Hill, and Markham built in the 1990s to 2010s with central AC, electric water heaters, and potentially EV chargers usually need 22kW. Large custom homes exceeding 3,500 square feet with multiple HVAC zones, pools, and high-demand electrical systems may need even larger units — 30kW to 48kW models are available but push installed costs to $15,000 to $25,000.

One sizing mistake to avoid: do not undersize to save $2,000 on the upfront cost. An undersized generator that overloads during peak demand will shut down on overload protection, leaving you without power until the load is reduced. Conversely, modest oversizing is acceptable — a 22kW unit running at 60 percent capacity is perfectly efficient and gives you headroom for future electrical additions like an EV charger. Your electrician's load calculation is the definitive answer for your specific home. Toronto Electrical Repair can match you with licensed electricians who perform load calculations and generator sizing as part of their installation service.