Propane
- Convenient when the house already has a gas line or a large propane tank.
- It burns cleaner and does not degrade over time.
- It needs a pressurized tank and specialized delivery, sometimes hard to get during a major storm.
- In deep cold, a propane tank delivers less gas: the tank must be sized for a Quebec winter.
Durability: 1,800 or 3,600 rpm
- Most residential propane generators are air-cooled and run at 3,600 rpm: the engine turns twice as fast to make the same 60 Hz, which wears parts faster.
- Our Perkins diesel generators run at 1,800 rpm, with liquid cooling and pressure lubrication, like an industrial engine.
- As a rough order of magnitude, a small air-cooled propane set at 3,600 rpm lasts from a few hundred to about 1,000 running hours, versus 6,000 to 10,000 hours for a liquid-cooled set at 1,800 rpm. And a diesel engine generally lasts several times longer than a spark-ignition engine (gasoline, propane, natural gas).
- For a few hours of outage a year, a propane unit may be enough. For long outages, frequent use or a farm, a diesel at 1,800 rpm makes the difference.
Energy per litre
A litre of propane holds about a third less energy than a litre of diesel (about 25 MJ versus 39 MJ). At the same power, a propane generator burns more litres, and needs a bigger tank for the same run time.
Diesel
- An industrial diesel engine is built to run for a long time: our Perkins generators are designed for heavy-duty use, 24 hours a day.
- The tank is built in, 200 to 600 L depending on the model: run time is counted in hours or days, without waiting for a gas delivery.
- The block heater is included: the generator starts even in deep cold.
- Diesel needs a little care: keep the tank full to avoid condensation, and service at 250 hours (oil) and 500 hours (fuel filter).
In short
- Best for: propane = home already on gas, short outages; diesel = farms, businesses, job sites, remote regions, long outages.
- Winter: propane = tank to size carefully; diesel = block heater included.
- Engine speed: propane = often 3,600 rpm, air-cooled; diesel = 1,800 rpm, liquid-cooled.
- Continuous use: propane = limited; diesel = 24 hours a day.
Frequently asked questions
Does a propane generator last less than a diesel?
Often, yes: most residential propane units run at 3,600 rpm and are air-cooled, while an industrial diesel runs at 1,800 rpm with liquid cooling. The engine wears more slowly.
Does diesel start in winter?
Yes: our generators include a block heater and glow plugs, with the 15W-40 oil recommended by Perkins.
Does diesel keep?
Yes, with the tank kept full (less condensation) and water drained as the Perkins manual explains.
How much does a diesel generator cost?
From $12,500 (10 kW) to $49,000 (150 kW) before taxes, including a 2-hour load bank test and a 1-year or 1,500-hour warranty.
Also read: Farm generator: stationary diesel or PTO? · What is the best diesel generator in Quebec?