The Advantages
The Advantages
Choosing a Generator for the Home: Diesel vs. Gasoline vs. Inverter (Quiet)
UPSs and AVRs are excellent buffers for the first few minutes of an outage and for power quality. But what happens when the power goes out due to a severe snowstorm, fire, or local substation failure and doesn't come back on for 24 or 48 hours?
In these cases, the battery is not enough. We need our own, private power generation "factory": the Generator (H/Z - Power Pair).
Buying a generator for your home or cottage is a serious investment, but the variety on the market is often confusing. As engineers, we're going to break down the 3 main technologies you'll come across, listing the pros, cons, and most importantly, what kind of power each produces for your sensitive devices.
1. Gasoline Generators (The classic emergency solution)
They are the most common and affordable generators you will find on the shelves of department stores. They work with a classic four-stroke gasoline engine (like that of motorcycles or lawnmowers).
Low Initial Cost
It is the cheapest option to get many kW.
Portability
They are lighter than their diesel counterparts, making them easier to transport around a property or warehouse.
Easy Cold Start
They get on more easily in winter at low temperatures.
The Disadvantages
The Disadvantages
High Consumption
They "burn" a lot, which makes long-term use expensive.
The Corrosion of Fuel
Unleaded gasoline "spoils" (loses its octane and forms deposits) if left in the tank for more than 3-4 months. If you leave it unused all summer, it may not start in the winter.
Ideal for
Houses or cottages that have infrequent and brief vacations (eg 3-4 times a year). It is the "emergency tool".
2. Diesel Generators (The "Dog" of Endurance)
This is where we move into the "heavyweight" category. Diesel engines do not use spark plugs for ignition, but compression.
The Advantages
The Advantages
Heavy Duty
They are made to work non-stop. They can work 24/7 for days without straining.
Lower Cost of Use
Diesel is cheaper than petrol and the engine consumes less (it is more efficient).
Fuel Safety
Diesel lasts much longer in storage and, importantly, is not as flammable as petrol, making it safer to store in the garage.
The Disadvantages
The Disadvantages
Weight & Volume
They are extremely heavy. You don't move them easily. They require a fixed installation point.
Noise & Cost of Ownership
They are more expensive in the market and make a deafening noise. That's why the good (and more expensive) diesel generators come "enclosed" (inside a large soundproof metal box).
Ideal for
Apartment buildings, businesses, or homes in remote mountains where a power outage can last for days and the generator must run non-stop.
3. Inverter Generators (The Modern, "Smart" Technology)
Here lies the revolution of the decade. Conventional generators (petrol and diesel) always run at constant, high RPM (typically 3,000 rpm) to put out 50 Hz of current, regardless of whether you've connected just a light bulb or an entire oven! This means constant noise and wasted fuel. Also, their current often has "fluctuations" (impurities), which can "burn" your expensive laptop.
Inverter generators (which usually burn gasoline) solve all these problems.
How they work
The motor first produces three-phase alternating current, converts it to direct current (DC), and then a microprocessor (inverter) converts it back to alternating current (AC).
The Advantages
The Advantages
Pure Sine Wave
The current they produce is "cleaner" even than that of DEDDIE. It is 100% safe for computers, medical machines, televisions and sensitive gas boilers.
Dynamic Turns (Eco Mode)
The engine adjusts its revs depending on what you ask for. If you turn on only one TV, the generator "drops" the revs to idle. If you turn on a water heater, it "marches".
Quiet
Thanks to Eco Mode and their closed, suitcase-like plastic enclosures, they are extremely quiet.
The Disadvantages
The Disadvantages
Higher Cost
They are the most expensive per kW.
Limited Power
They usually come in small sizes (2 kW to 4 kW), although there are some larger ones. They can't lift an entire, huge house with 3 air conditioners at once.
Ideal for
Modern homes full of electronics (TV, Router, PC), camping, food trucks, and generally cases where quietness and power quality are an absolute priority.
Summarizing (What to choose?)
- If the budget is "tight", you don't have particularly sensitive electronics and just want to turn on the lights, fridge and oven 2 times a year when the power goes out rightarrow Conventional Gasoline.
- If you have a large house or business, you need a lot of kW (eg 10kW+) and you want the generator to work non-stop for 3 days in the snow rightarrow Diesel (Closed type).
- If you want to protect your gas boiler, your expensive Home Cinema, your telecommuting (PC/Router) and you don't want to disturb the neighbors with the noise rightarrow Inverter.
Next Step: You have decided which type of engine you prefer. But how big should the generator be? If you get a small one, it will "go off" when you turn on the water heater. Continue to our practical guide: How Do I Calculate a Generator's kVA: Sizing Guide to Lift Emergency Loads, to do the maths before you buy.
Related Articles
How to Calculate a Generator's kVA: Sizing Guide to Lift Emergency Loads Automatic Transfer Switch (ATS): How the generator starts up on its own when the power goes out Manual Mains/U/Z Switching at the Electrical Panel: Legislation, Safety and How to Install Home Energy Storage vs. Generators: The future of backup and cost comparison
Electrical Supply, Power & Autonomy
Return to category.
Go to categoryCentral Guide
Return to the central guide.
Go to guide