Rational Preparedness

What are Inverter Generators vs Conventional Generators?

Inverter Generator Vs Conventional

 Know your power source.  Inverters, inverter generators, and conventional generators

There are two ways to get AC power.  One is with an inverter and one is with a generators that naturally creates the AC wave, as it turns.  Inverters can be paired with solar systems, generators, or cars/boats etc.  So, let’s start the discussion with them.

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Contents

Inverters

Inverters take DC power and convert it to AC power.  You can plug them into your 12v power socket in your car, they might be a part of your RV, and they are what solar energy is converted to AC power with.  Some newer generators also use them as I will discuss below.

Depending on quality, an inverter can produce power that is harmful to sensitive appliances, like electronics, if used extensively.  For example; a laptop transformer rectifier (TR) can wear out more quickly, with a low quality inverter.

You usually don’t hear the word rectifier used with transformer but that’s what all of these large plugs on your electronic devices are.  They are made of of two separate components.  The transformer changes the voltage to what you device needs and the rectifier turns the power into DC power your device needs.

AC power voltage follows a smooth sine wave pattern, from positive to negative voltage.  Some inverters have block shaped waves or morel likely jagged waves that aren’t so smooth.  This is where the excessive wear to your devices can come from.  The power can also be noisy in headphones and speakers or audio recording.

What to look for in an inverter
What you want is an inverter that has a true sine wave output.  Most inverters that have this feature will advertise it.  Also, most of the popular inverter generators come with true sine wave inverters.  Here is an example of a pure sine wave inverter I found on Amazon.  It’s the Microsolar 12v 100w inverter.

Be sure to check out the article on Generator Fuel types

Inverter Generator

An inverter generator has a more complex electronic component to it than a conventional generator.  These generators start with 3-phase AC power, like a conventional generator.  They convert that 3-phase power, into DC power, using a rectifier.  Then they invert the power into a single phase of AC power, using inverters as discussed above.

An inverter allows for a number of things.  First, it allows for a generator to me smaller and useful at the same time.  If a generator is only 1600 watts and that is split between three phases, you could not run a refrigerator on it, or a microwave.  The inverter fixes that problem with small generators.  The inverter electronics also allow for the generator to throttle up and down, depending on load.  This saves fuel and noise.

Part of the electronics in an inverter generator also produces less and less power over its life.  I’m not sure how generator manufacturers deal with that reality.  Maybe some oversize the electronics in anticipation of that and others don’t.  If they did this over-sizing, you would never know the difference over years.  This would be information that might be difficult to get in the market because most customers are wholly unaware of this issue.

See some Examples of inverter generators on Amazon: The Generac iQ, the Yamaha EF2000iS, and the Honda EU2000I

 

Profile image of generac IQ556921_silo_300x300

Conventional Generator

A conventional generator is a simpler machine that has been around for many decades.  It generates a constant voltage by maintaining a constant engine speed.  There is usually an idle engine speed for not producing power and an operating speed, when you need power.  That’s it.  Because it doesn’t have complex electronics to do this, these generators cost significantly less to purchase per watt, than inverter generators.  They also tend to produce more power.

Because the engine must maintain a constant speed, the generators are generally louder and use more fuel.  If your goal is to use these only for emergencies, the fuel cost would likely be far less than the money you save buying the unit.  On the other hand, if you want to use it regularly, for RVing, the cost of fuel might make the inverter more cost effective.

There are fewer components to malfunction, in a conventional generator.   Inverters have a useful life and depending on quality, it may be more or less than the useful life of the engine.

4 Comments

  1. garth

    in case of emergancy can i run my high effeicent furnace with a regular generator or do i have to use a pure sine wave generator

    Reply
    1. Joe (Post author)

      A conventional generator produces a pure sign wave, by its nature. An inverter is trying to imitate what a conventional generator does. This is true of battery powered inverters and inverter generators. So, yes, a conventional generator would be good for a furnace as long as it is powerful enough.

      Reply
  2. Genma

    Very useful post. Which generator is best for home usage and can handle high voltage appliances?

    Reply
    1. Joe (Post author)

      Voltage is measured as a difference in potential. If you plug a meter into the power outlet and the other end into the ground on the same outlet, you get about 115v. The difference between the power, 115v and the ground, 0 volts is the 115V. Take a look at the sine wave in the section above about inverters, where I’m talking about AC power.

      Now imagine that instead of putting your second meter lead into the ground, you plug it into a 2nd power in the socket. Except instead of the sine wave on the 2nd power (the second phase) is not matching the one there, it is out of sync with it. When the one power is very negative, the other power is very positive. Between each of these 115v power phases, you have more than 115v difference in potential. This is how 220v power is achieved in the home.

      A generator naturally generates this power because it has 3 phases. In an inverter generator, all 3 phases are electronically melded into a single phase, as described above, so most if not all of them don’t have 220 outlets. It would be possible for one to have one though because even an inverter generator has the phases needed.

      Many conventional generators come with 220 outlets on them. Typically if an appliance is drawing 220v of power it is because it is also drawing more current and the higher voltage makes that easier to do. So, you need to be especially aware of the wattage of the appliance vs the generator you are using. You can’t go wrong with a stand by (whole house) natural gas generator.

      If the standby generators are outside your budget there are portable generators that can do the job too. Just be aware of the capacity. Some of them are quite capable of running big appliances though. Here is an example of one capable of doing the job. It’s a Champion 7500 watt generator.

      I noticed it says 240. 220-240 are basically the same thing from the user perspective.

      Reply
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