Propane vs Natural Gas Generator: Which Fuel Is Better for Ontario?

Ontario homeowners keep learning the same hard lesson. Winter ice storms, spring wind events, and summer transformer failures knock out power for hours or days. A 2024 Hydro One reliability report showed that rural customers in parts of central Ontario averaged more than 14 hours of outage time per year. Urban customers face shorter but still disruptive outages. When the grid fails, a standby generator can keep sump pumps, furnaces, freezers, and medical equipment running. Before you buy, read our emergency power statistics for 2026 and our Ontario ice storm prep guide to see what you are actually preparing for.

Fuel choice is the first decision that locks in your generator’s cost, maintenance, and reliability. Propane and natural gas both feed clean-burning, long-life standby engines, but they behave very differently during a regional emergency. Natural gas arrives through a buried line that normally stays on during local outages. Propane sits in a tank on your property and does not depend on a utility. The right answer depends on whether your home has a gas meter, how long you need to run, and whether you can tolerate a fuel delivery delay. Use our generator sizing guide before you choose a fuel or a wattage.

This comparison is based on published manufacturer data, Ontario installation code, and real-world service patterns. We reviewed generator specifications from Generac, safety standards from the CSA Group, and wiring rules from the Electrical Safety Authority. We looked at 20 to 22 kW air-cooled standby generators because they are the most common size for whole-home backup in a 2,000 to 3,000 square foot Ontario house. Price figures are in Canadian dollars unless noted and include typical equipment, materials, and licensed labour ranges.

You do not need to solve every variable today. Start with your fuel supply. If a natural gas meter is already on the house, a natural gas generator usually costs less to run and avoids tank placement. If you are rural or already use propane for heat, the same tank can often supply your generator. We have also compared the major standby brands in Generac vs Kohler vs Briggs. The rest of this article breaks down fuel storage, running costs, installation rules, performance, and cold weather behaviour item by item.

How Do the Top Options Compare?

Prices are estimates for a 20 to 22 kW air-cooled standby generator installed by licensed Ontario trades. Equipment-only Amazon search links do not include transfer switch, pad, trenching, gas fitting, permits, or taxes.

1. Fuel Storage and Outage Security , Best for rural homes without a gas line

Propane gives you physical control of your fuel. A 500-gallon residential tank holds about 400 usable gallons after the 80 percent fill limit. Pair that with a Generac Guardian 22 kW on propane, which burns around 2.1 gallons per hour at full load and 1.2 gallons per hour at half load. At half load, 400 gallons works out to roughly 333 hours of runtime, or nearly 14 days. That is the kind of reserve you need for a prolonged winter outage. If you already heat with propane, the same tank can often feed the generator. Natural gas has no on-site reserve. The line feeding your generator is a utility asset. That is normally a benefit because you never schedule a propane delivery. But if a regional emergency damages gas infrastructure, you cannot refill the line. For week-long outage planning, fuel security affects every part of your home backup plan. Downsides are honest. Propane tanks need room, a stable concrete pad or underground trench, and clear access for the delivery truck. A new 500-gallon above-ground tank often costs $1,800 to $3,500 CAD installed. Underground tanks are cleaner looking but cost more and may need corrosion protection. Natural gas removes that yard clutter, but you inherit a dependency on the gas utility’s own emergency response.

Key strengths:

• ✅ On-site fuel keeps the generator running when the grid and gas utility fail.
• ✅ Tank can be sized for multi-day or multi-week outage runtimes.
• ✅ No fuel delivery scheduling if your home already uses propane for heat or cooking.
• ❌ Tank takes yard space and needs a clear path for the delivery truck.
• ❌ Usable fuel is only about 80 percent of tank capacity, so plan refills before a storm.
• ❌ New propane tank installation adds $1,800 to $3,500 CAD in upfront cost.

Who it’s for: Choose propane if your home is rural, already uses propane, or you want a physical fuel reserve that does not depend on a utility.

2. Running Costs and Fuel Efficiency , Best for urban homes with an existing gas meter

Natural gas usually wins on hourly fuel cost in Ontario cities. A 22 kW air-cooled unit at half load consumes about 228 cubic feet of natural gas per hour. At roughly $0.014 per cubic foot, that is about $3.19 per hour. The same unit at half load on propane burns about 1.2 gallons per hour. At a delivered propane price of $2.80 per gallon, that is $3.36 per hour. The difference grows at full load because delivered propane often spikes to $3.50 or more per gallon in winter. Propane pricing is less stable because you buy from a supplier. Contract pricing can lock a winter rate, but you are still paying for delivery and tank rental unless you own the tank. Natural gas is regulated by the Ontario Energy Board, so the rate structure is public. That said, both fuels produce similar generator efficiency. The real savings come from how your house uses the generator and how often you exercise it. Check the Generac Guardian 22kW on Amazon to compare equipment pricing before you calculate fuel. One hidden cost is run time during weekly exercises. Most standby generators run for 10 to 15 minutes each week. Over a year, that is about 10 hours of no-load or light-load operation. Natural gas makes that trivial. Propane also handles it well, but you will notice the tank level dropping over a year even without an outage.

Key strengths:

• ✅ Natural gas hourly fuel cost is usually lower for urban Ontario homes.
• ✅ No delivery fees or tank rental for natural gas.
• ✅ Propane contract pricing helps lock in winter fuel costs.
• ❌ Delivered propane can spike during high-demand cold snaps.
• ❌ Natural gas regulated rates still increase over time.
• ❌ Propane tank ownership adds recertification and leak test responsibilities.

Who it’s for: Choose natural gas if you already have a gas meter and want the lowest typical hourly operating cost.

3. Installation, Codes, and Ontario Requirements , Best for homeowners who want a clean permitted install

Both fuels require a transfer switch that isolates your generator from the utility grid. In Ontario, the Electrical Safety Authority requires a licensed electrical contractor to perform the wiring. That is not optional. A standby generator also needs a natural gas or propane connection made by a TSSA-licensed gas fitter. The generator itself must carry certification from CSA Group or another recognized testing lab. Natural gas installations often look simpler because the line already runs to the house. The problem is capacity. A 22 kW standby generator may need 250,000 to 300,000 BTU per hour from the meter. If your existing gas meter and regulator cannot supply the house plus the generator, Enbridge or your local utility must upgrade the service. That upgrade can cost $500 to $2,000 CAD and add weeks to the project. Propane installations need a tank, regulator, and buried or protected line, but they put you in control of the fuel side. Do not attempt any line-voltage hookup yourself. A generator wired incorrectly can backfeed the grid and kill a utility worker. Our generator safety tips cover clearances, carbon monoxide, and transfer switch basics. If you are comparing specific standby brands, the Kohler 20RESCL on Amazon is one common 20 kW air-cooled option, but your installer must confirm the fuel type and local code before you buy.

Key strengths:

• ✅ Both fuels require a utility-approved transfer switch, which protects your home and line workers.
• ✅ Natural gas uses an existing line, so no tank excavation or large yard space.
• ✅ Propane can be installed on rural lots without a gas main.
• ❌ Permits and licensed trades add $1,000 to $3,000 CAD in labour.
• ❌ Natural gas meter upgrades can delay installation by weeks.
• ❌ Propane tank placement must meet strict clearance rules from windows, doors, and ignition sources.

Who it’s for: Choose either fuel once you confirm your property meets Ontario siting, clearance, and meter-capacity rules.

4. Generator Performance and Maintenance , Best for homeowners comparing real-world output

The same air-cooled generator often produces more running watts on propane than on natural gas. A Generac Guardian 22 kW is rated at 22,000 running watts on LP and 19,500 running watts on natural gas. That 2,500-watt gap may seem small, but it matters if you sized the unit for a well pump, electric range, or heat strip. Before choosing a fuel, confirm the derate with the manufacturer data sheet, not the box label. Propane burns cleaner in most engines. It produces less carbon buildup, which can extend oil life and reduce spark plug fouling over years of weekly exercise. Natural gas is also clean-burning but slightly less energy dense per cubic foot. Both fuels need basic maintenance every 100 hours or two years. That includes oil, oil filter, air filter, spark plugs, battery test, and valve clearance after several hundred hours. Use our continuous runtime guide to understand maintenance intervals during long outages. One practical difference is fuel system inspection. A natural gas generator relies on the utility to maintain the meter and regulator. A propane generator leaves tank recertification, line pressure checks, and leak testing to you or your supplier. Neither fuel is maintenance-free, but propane has one more outdoor component that weather can damage.

Key strengths:

• ✅ Propane often delivers higher running watts on the same 20 to 22 kW air-cooled unit.
• ✅ Propane burns cleaner and can reduce carbon deposits in the engine.
• ✅ Natural gas has no tank to recertify and no liquid leak test to arrange.
• ❌ Natural gas units lose rated output compared with the same generator on propane.
• ❌ Propane regulator freezing or undersizing can cause rich running and poor efficiency.
• ❌ Both fuel types need annual oil, filter, spark plug, and battery checks.

Who it’s for: Choose propane if you need the highest continuous wattage from a specific 20 to 22 kW air-cooled standby unit.

5. Cold Weather Reliability and Emissions , Best for exposed rural and northern Ontario properties

Cold weather punishes both fuels, but in different ways. Propane vapour pressure drops as temperature falls. Above-ground tanks can struggle below minus 25 degrees Celsius because the liquid propane cannot vaporize fast enough to feed a 22 kW engine. A buried tank or an approved tank heater solves that problem. Natural gas does not need vaporization, but exposed meters and regulators can freeze when wet snow packs around them. A roof or meter cover helps. Emissions are another tie-breaker. Natural gas produces less carbon dioxide per unit of energy than propane, but neither fuel is clean enough to run inside a home, garage, or attached breezeway. Both produce carbon monoxide, an odourless gas that kills. Keep the generator at least 5 feet from doors, windows, and vents. For a zero-fuel alternative, consider a whole house battery backup if you cannot meet those clearances. For northern Ontario, propane offers one major resilience advantage. You can fill the tank before a storm and keep a generator running even if roads close. Natural gas works well until the utility has an issue. Most Ontario gas utilities maintain good winter reliability, but a third-party line strike or flooding can still interrupt service for hours or days.

Key strengths:

• ✅ Propane stored on site keeps working when snow closes delivery roads.
• ✅ Natural gas lines remain reliable in most winter storms if the meter is protected.
• ✅ Both fuels can be fitted with cold-weather kits for oil and battery warmers.
• ❌ Above-ground propane tanks lose vapour pressure below minus 25 degrees Celsius.
• ❌ Natural gas service can be interrupted by line strikes or utility work.
• ❌ Both fuels produce carbon monoxide and require a CO detector plus outdoor clearance.

Who it’s for: Choose natural gas if you live in a city or suburb with buried gas lines and rare delivery issues.

Frequently Asked Questions

What Should You Remember?

• Fuel security: Propane keeps working if the gas grid fails; natural gas depends on the utility.
• Running cost: Natural gas is usually cheaper per litre-equivalent, but rates vary.
• Sizing: A 20 kW generator loses some output on natural gas compared with propane.
• Installation: Ontario requires a licensed electrician and a transfer switch for home backup.
• Cold starts: Propane vapour pressure drops in extreme cold; insist on a heated tank or bury the line.
• Maintenance: Both need annual checks but propane tanks need leak tests.

This article is for general information only. Always follow manufacturer instructions, local electrical codes, and hire a licensed electrician for transfer switches and standby generator installation. Carbon monoxide is deadly , never run a generator indoors.