Inverter Generator versus Conventional Generator

Inverter Generator versus Conventional Generator

The first generator can be traced back to the 18th Century when James Watt noticed that steam engines wasted a lot of heat energy.  He designed contemporary generators that would prevent energy wastage. In the 1800s, Michael Faraday invented the Faraday Disk that formed the first electromagnetic generator.  Through the end of the 1870s, scientists used the AC (alternating current) and DC (direct current) generators.

Further research by scientists such as Nikola Tesla and businesses such as GE, Siemens, Westinghouse, and Kohler improved the design of generators. Today, Australia is a leading producer and market of generators. These machines are generally used for outdoor activities which require the use of appliances off the grid. Before you venture out, you should choose from these three types: conventional generator, portable generator, and inverter generator. What are these generators? Let’s find out.

Conventional Generator

A conventional generator has a gas- or propane-powered engine attached to the alternator which produces AC or alternating current.  Others generate power in DC or direct current. A conventional generator is usually bigger and heavier than the other types.

How does it work?

A generator works when the engine motor produces mechanical energy and then supplies this energy to the alternator which generates the mechanical output. This alternator constitutes a rotor and stator. The rotor (made of copper) wounds around a shaft which is connected to a motor that spins the shaft. The shaft (conductor or rotor) has electrons that become energised because of the spinning motion. This results in the formation of the so-called electromagnetic field.

The field goes to the stator which is a static winding which fits around the rotor without touching it. When the electromagnetic field moves around the stator, it produces a voltage – known as the magnetic induction. This magnetic field changes when the polarity goes from positive to negative, which then results in the pulse between the low and high charge. This pulse generates the sinewave. To keep the voltage constant, the generator must use the automatic voltage generator.  The engine uses the potential energy from the fuel to produce this mechanical energy.


Generators consist of an engine motor, fuel tank, battery charger, cooling, voltage regulator, lubrication system, and alternator. In some types, there might be extra LED indicators and control knobs.

Steps in Using a Conventional Generator

  1. Read the instructions manual, focusing on the processes, safety info, and warranty.
  2. Place the generator in a cool and dry place which is at least 20 feet away.
  3. Check the machine’s fuel gauge.
  4. Check the oil level and use the oil type recommended by the manufacturer.
  5. Check the oil filter and ensure that it has no debris or dirt.
  6. Ensure that the circuit breaker is in the off position before the running the engine.
  7. Turn on the fuel valve.
  8. Start the engine.
  9. Connect the appliances or devices.
  10. After using, turn off the generator and let it cool before refuelling.
  11. Keep it in a cool dry place and store according to the manufacturer’s instruction.

Safety Precautions

  1. Never use generators indoors or in a closed space where carbon monoxide can accumulate.
  2. Take precautions when storing gasoline because it ignites easily.


Conventional generators come with large tanks which are more than enough for your average energy needs.  A single conventional generator would run 24 hours in one full tank, which is adequate for long-term stationary or outdoor work.


Conventional generators are bulky and heavy because of their alternator and built. You won’t expect a stable frequency from a conventional generator because it doesn’t use an inverter and true sine wave technology which is necessary for a clean power output.

It is not advisable to run sensitive electronics on conventional generators because of voltage spikes which can ruin the electronics’ circuit.

Conventional generators also produce more noise and heat. At the same time, they waste more fuel compared to inverter generators. For instance, a conventional generator uses a lot of fuel when running continuously because it cannot adjust to the number of appliances connected to it.  In comparison, the inverter generator can change its power output depending on the load.

Inverter Generator

An inverter generator contains an inverter that replaces the heavy and bulky alternator found in conventional generator. This results in the portability of the inverter generator.

How does it work?

An inverter generator uses an inverter to convert a DC into AC and converts it again into a clean DC. This type produces more AC power output per engine rotation. The inverter module converts the DC power into a 60 Hz and 120-volt power which is no longer a block wave but a sine wave. This AC output features less than 6% of total harmonic distortion (THD) which is recommended for sensitive electronics such as portable power tools, laptop, laboratory, and medical devices.


  1. Quiet operation. At 58 decibels, an inverter generator is quieter than a conversation. A conventional generator, on the other hand, can wake you up with the sound like a circular chain saw. You could run an inverter generator without disturbing the peace of your neighbourhood or construction workers napping at their breaks.

    This type of generator uses an attenuating housing to reduce noise; thus, maintaining volume at comfortable 50 to 60 decibels.  This noise reduction feature makes inverter generator ideal for food parties, hospitals, laboratories, churches, construction, and offices. The following are the table of decibels.

    Noise source Decibels
    Jet engine 140
    Stadium crowd noise 130
    Rock band 110
    Sporting event 105
    Conversation 60
    Gentrax Inverter Generator 58
    Whisper 30
  2. Less vibration. Unlike a conventional generator, an inverter produces less vibration. The more the vibration a generator generates, the more it wears down its mechanical parts and causes unwanted vibration disturbances.

  3. True sine-wave. An inverter generator produces a power output frequency with a true-sine wave. Technically, a true sine wave features a smooth crest and throughs as opposed to the irregular pattern of a modified sine wave. If you use conventional generators with sensitive electronics, you run the risks of damaging its circuit parts or have generators produce an efficient power output.

    The true sine wave is also fuel efficient which means you can generate more power output from the same amount of fuel. Whilst you may also run devices in conventional generators, these devices produce hum or some sort of noise distortion such as in the case of a radio or telephone. In addition, conventional generators can cause premature equipment failure, automatic reboot, data error, system lock-up, and excessive service calls. The following are devices with sensitive electronics:

    Plasma TV
    Power tools
    Controls found in HVAC systems
    POS Systems
    AV Systems
    Gaming consoles
  4. Inverter generators are lightweight and portable, owing to the generator’s comfortable grip handle and durable wheels. You can carry them around for your outdoor activities in camping, hiking, tailgating, and outdoor parties.

  5. Because of its power efficiency and less vibration, inverter generators can last longer. On top of that, its housing is made of stainless steel and high-density plastic or HDP which protects electronics against constant weathering.

  6. Clean power. Using a double conversion method from DC into AC into DC, the inverter can produce clean power with a true sine-wave frequency. Its inverter microprocessor can keep a sine wave a thousand times per second and uses a capacitor to correct any voltage change and any smallest voltage variation. This results in a less than 3% of total harmonic distortion or THD.

  7. Reduced maintenance. Due to its reduced noise, vibration, stable power output, and quality material, an inverter generator can provide you with seamless operation without the need for frequent repairs or replacement of parts. You don’t have to worry about the inefficient power supply.

  8. Parallel capable. You can double the power of an inverter generator by using it along with the same size and specifications.

  9. Fuel saver. Inverter generators can save you some fuel through its economy mode feature. The machine can adjust its speed so that it can use only the necessary fuel to run a specific device. Conventional or common generators run at constant 3600 rounds per minute whilst the inverter can vary its RPM; thus being fuel-efficient.

  10. Environment-friendly. Because inverter generators need less fuel and run more efficiently, they emit less carbon dioxide, compared to conventional generators.


  1. More expensive. Inverter generators are more expensive than their conventional counterparts.

  2. Less fuel capacity. Some inverter generators have less fuel capacity compared to conventional generators.

How to choose among the generators

  1. Decide what your intended use is. Are you going to use it for professional, outdoor, home, office, or commercial purposes? Professional use includes laboratory, medical, research, and scientific activities. Outdoor activities include camping, 4WD adventure, hiking, fishing, and island hopping.

  2. Calculate your appliance wattage. This will help you decide the power output rating of a generator. Here’s how:

    To know the number of watt-hours used per day, multiply the unit’s wattage by the number of hours used. For instance, a 65-watt laptop X 10 hours = 650 watt-hours per day.

    Convert this watt into kilowatt hours. 1 kW = 1000 W. To calculate: 650 / 1000 Watts = 65 kilowatts.

    If you want to know the usage per month: 650 kw X 30 days = 19,500 kw.

    Add the watts of each appliance and the convert the resulting watts into kilowatts.  Match this to the specification of your chosen generator.

  3. Consider portability. If you often venture out, think about the portability features such as wheels, comfortable grip, and lightweight built. Otherwise, if you want a stationary generator, you can use a conventional generator.

  4. Decide what fuel the generator uses. If you’re buying a diesel generator or a gasoline generator, check if this fuel is available or common in your area. Most generators use these fuels.

  5. Gasoline is easily obtained and adds portability to small generators. However, this fuel is highly flammable. It also has a short shelf life of one year, and it can be expensive.  Sometimes, it is not available during power outages.

  6. Bio-diesel is common, the least flammable among fuel sources, and a clean alternative. Without additives, it could last only 18 to 24 months. It also needs the correct percentage of fuel and oil mixes.

  7. Diesel is a less flammable fuel, easily obtained, and inexpensive. It can be used in freezing temperature with fuel additives. However, wet stacking or over fuelling can cause the engine to smoke because of its carbonised injectors.

  8. Natural gas offers a clean and abundant fuel source. This one offers a quieter engine and provides no problems with wet stacking found in diesel fuel. However, it may not be available during natural disasters. In fact, it is unavailable in some areas.  It also begins to derate below +20 degrees.

  9. Opt for generators according to their fuel capacities. You may opt for generators that use small, medium, and large fuel tanks. For heavy and long-time use, a large capacity generator with a fuel tank of about 10” to 12” tall can run for 12 hours, whilst a 36” one can run for 72 hours. Generators can also be single fuel, bi-fuel, or tri-fuel.

  10. Single fuel. Choose this if you are sure that the fuel is common and inexpensive in your area.

  11. Bi-fuel. Consider it if you want the benefits of two fuels. For instance, you can choose both diesel and gas, and use the diesel in case of natural gas unavailability. You can benefit from the power of diesel and at the same time the abundance of a natural gas.

  12. Tri-fuel. It is the best of the three. You can enjoy the versatility of using three fuels – propane, natural gas, and diesel.


Depending on your budget and needs, you could choose from conventional or inverter generators. Inverter generators can be expensive, but in the long run, you could save money because of its fuel and power efficiency. In addition, you will enjoy a quieter, stable, and clean power.

How can Gentrax help you?

Gentrax helps you choose a quality generator for your professional or outdoor use. Since 1989, Gentrax has been helping Aussies connect to a reliable, affordable, and portable electricity source. Learn more at

Reading next

The Ultimate Cheat Sheet on Portable Inverter Generators
Which is the Best Generator for RV Camping?