The Advantages of Pure Sine Wave Inverters Over Modified Sine Wave Inverters

People are more willing to invest in solar energy. This is due to the economic component, the availability of solar radiation for everyone, and the environmental friendliness of the generated electricity. When buying solar structures, they are mostly purchased already with all the components.

Source: Mercury Direct

But each element is of different types, on which the technical features of the solar station depend. One of these components is an inverter. In the article, we will try to explain what pure sine waves mean and quasi-sine waves, what is the difference between a pure sine wave and a modified sine wave is, and what type of inverter is better to invest in.

Which Types of Solar Charge Controllers Are Better: Modified Sine Wave or True?

Inverters in solar constructions are one of the main elements. Sinewave inverter comes in two types – pure sinewave and modified sine wave. Each type is designed for specific tasks in household power consumption, and its choice should depend on these goals.

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Solar controllers convert constant energy from solar modules into alternating current, which is necessary for powering electrical appliances in a house, van, or boat. The main differences between modified vs pure sine wave inverters are the efficiency of devices and cost.

A Solar Inverter, Why Is It Needed?

An inverter is a gateway between your electrical appliances and photovoltaic panels. The task of the inverter is to change the direct current (DC) into alternating current (AC), which is necessary for power-consuming devices. Inverters also affect voltage changes.

The Purpose of the Inverter in Solar Installations

It is impossible to power commercial equipment and household devices without an inverter. The inverter uses sine wave technology to change DC to AC. The device takes the DC voltage from the panel and changes it to a sinusoidal curve below 0 volts. The resulting curve is called a modified sine or sinusoid. To imitate a modified sine, some modified waves go through several stages.

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This whole process of converting current into a pure sine wave inverter runs more smoothly. The performance characteristics of inverters depend on the smoothness of solar energy conversion. Modified sine wave inverter vs pure sine wave inverter differs because it creates noise and reduces the frequency of the current. But quasi-sinusoidal inverters are cheaper.

Definition of Pure Sine Wave Inverter

In the technical confrontation of pure sine wave inverter vs modified, a pure sine wave wins in several characteristics. First, you need to determine what is pure sine wave inverter. This term refers to devices capable of generating power from solar modules equivalent to the power supplied by the utility grid. You can’t do without pure sine wave inverters if you need to power sensitive devices:

• Digital TVs
• Laptops and electronic gadgets
• Equipment with AC motors and digital timers
• Sensitive medical devices
• Battery chargers
• Variable speed motors
• Audio, video equipment
• Satellite systems
• Laser office devices

These devices will not be productive without pure sine wave inverters. The advantages of a pure sine wave inverter vs a modified sine wave inverter are the following:

• Supply utility-class voltage
• Most equipment on the market is focused on pure sine wave
• Protects electrical appliances, working without interference
• Generate smoother and cleaner electricity

The disadvantages of pure sine wave inverters are only at a higher cost than a modified sine wave.

Definition of Modified Sine Wave Inverter

A modified sine wave inverter is a cheaper analog of inverters suitable operating electrical equipment with a low sensitivity threshold to power fluctuations. The modified sine wave power inverter creates a quasi-sine waveform that is less smooth than a true sine wave.

Source: EngineersGarage

A sudden polarity reversal — from positive to negative — causes the susceptibility of the modified sine wave inverter to power fluctuations. The wave of this type of inverter has a square and stepped pattern, where the polarity changes back and forth, which negatively affects the operation of sensitive equipment, a hum can be heard when devices are connected, or some will not start at all.

The modified inverter has less sine wave power. The main advantage of a modified sine wave inverter vs a pure one is lower cost.

What Can I Use a Modified Sine Wave Inverter For?

Having figured out what a modified sine wave vs pure sine wave inverter is, we can list in which cases the purchase of cheaper analogs of sine wave power inverters is relevant. If solar panels do not power AC motors or operate fragile medical equipment, then problems with retrofit equipment may not arise.

Select the modified sine inverter to use in:

• Simple systems where there is no AC motor
• Old TVs
• Water pumps
• Chargers for gadgets
• Power supplies for fluorescent lamps
• Dimmers

Some AC-powered devices may operate on a modified sine wave, but their readings may not be correct, for example:

• Refrigerators
• Large home appliances
• Most power tools
• Microwaves
• Compressors

Even some fluorescent lamps may make a sound when turned on and dim. When comparing pure sine wave vs modified sine wave inverter for AC motor operation, the true wave should be preferred. Otherwise, the engine will heat up faster, vibrate, and shorten its life.

What Are the Advantages and Disadvantages of Utilizing a Modified Sine Wave Inverter?

The main difference is the price if we highlight the advantages of modified sine vs pure sine. The cost of a pure sine vs modified sine inverter is 1:3. The average price for a modified sine wave device is $60-600, while a pure sine wave inverter costs $150-900.

The disadvantages of the modified inverter are the following:

• High risk of interference and noise
• Low efficiency, which will lead to more electricity consumption
• Inability to connect sensitive devices

Manufacturers claim that the inverter’s power is enough to power laptops, but the use of quasi-sine wave technology will reduce the performance of the computer’s battery.

Sine or Square Wave: Which Inverter Is Right for Me?

Pure sine wave inverter efficiency depends on the power of the device. Inverters vary in size, and power is rated in watts, just like PV modules. For the device to handle all the energy coming from the panels, it must be selected in a suitable size with the same DC rating. If you have a solar installation with a capacity of 4000 W, then the inverter power should be 4000 W.

When choosing between pure sine vs modified sine power inverters and direct, it is important to understand their differences. If the first two options are described in detail above, then the direct one should be discussed separately.

Source: Natures Generator

It is based on a square wave. That’s a modified sinusoidal inverter, but of the simplest design, which reflects in the cheapness of the device. It is compatible with simple appliances, tools, and universal motors. Due to the lack of advantages, it is rarely included with ready-made solar installations.

To understand which type of modified sine wave to pure sine wave inverter will be best to meet the energy needs of all home equipment, you need to answer a couple of questions:

• Is fragile medical equipment in use?
• What type of current is in use by household appliances motors?
• What devices can be powered by a DC adapter?

A pure sine wave inverter should be the first choice when in doubt. This way, you’ll ensure the whole machine works safely and efficiently.

Can I Utilize an Off-grid Setup With a Customized Sine Wave Inverter? What Is a Grid-tie System in Off-grid Solar?

In every person’s home, many appliances are powered by pure sine waves. If you switch to a completely autonomous solar system, the modified inverter will not be able to ensure the efficient operation of all electrical appliances; that’s why a pure sine wave inverter is what autonomous solar power plants need.

Source: Sunshine Solar

There is also such a thing as a grid system. That’s a semi-autonomous system for generating and storing solar energy on the grid. It allows you to take electricity from the network in case of a lack of electricity and redirect it back if the panels generate excessive energy. And in this case, installing an inverter with pure sine wave vs modified sine wave wins.

What’s the Final Word? What Should I Invest In?

Pure sine wave vs modified sine wave inverters wins for several reasons:

• Greater efficiency – by 30%
• Smooth energy
• Minimal risk of interference
• The longer service life of the device
• Possibility of use for any equipment

Cost should not be the deciding factor when choosing an inverter type. Selecting an inverter with a sinus wave that does not harm the equipment but will ensure its maximum productivity is important. On top of that, it’s crucial to understand the working principle and structure of a pure sine wave inverter and only then invest in the device.