Transformerless Inverter: Lighter, Leaner, and Smarter

The transformerless inverter is a true game-changer in renewable energy. It’s not just another option; it’s quickly becoming a favorite for many, thanks to its knack for pushing efficiency to new heights while keeping things sleek and cost-effective.

But what exactly sets it apart from the traditional inverters we’re used to? Apart from it not having a transformer, of course.

Well, you’ve come to the right place, as I’m breaking down how they work, how they stack up against conventional inverters, and what choosing one means for you. Below is a list of topics I’m covering. Feel free to tap the bullets to skip sections, but I do recommend reading from the top.

Transformerless inverters: What are they, exactly?

Transformerless inverters, or TL inverters, like their conventional counterparts, are the high-tech bridge between the solar panels on your roof and the appliances in your home. They’re in charge of converting direct current (DC) into alternating current (AC).

What makes them different is that they ditch the heavy internal transformer, opting instead for advanced electronic components like high-voltage MOSFETs, gate resistors, and special driver ICs.

This makes them lighter, more affordable, and more efficient while still ensuring that the solar output voltage is converted into the operating voltage your gadgets and appliances need.

How do transformerless inverters work?

Transformerless inverters employ a sophisticated, computerized, multi-step process to convert DC to AC.

The first step of the process involves adjusting the DC electricity produced by your solar panel to make it suitable for AC conversion.

After that, rapid electronic switching takes place. This is when the transistors or semiconductor devices that replaced the internal transformer switch on and off, creating a pulse-width modulated (PWM) signal that approximates AC.

Lastly, the PWM signal goes through a filtering process that further refines the waveform to match the standard-frequency AC that we all use at home.

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Also, a transformerless solar inverter has dual MPPT inputs.

MPPTs, or Maximum Power Point Trackers, are what’s responsible for dialing in the DC output from your solar panel to the DC required by the grid or to charge solar batteries. It’s a feature that every grid-tied solar energy system has.

The problem with most systems, however, is that one solar panel’s inefficiency can bring down the power output of the whole system.

With a transformerless inverter, though, that problem can be solved. You see, these inverters have two MPPT inputs. This allows you to put up solar panels on multiple sides of your roof without one’s inefficiency dragging down the other, resulting in a more efficient solar system overall.

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The downsides to a transformerless inverter

Ah, yes. Every rose has its thorns. For one, the lack of an inverter also means they lack electrical isolation between DC and AC circuits. This could potentially cause electric shocks, particularly if there’s a fault in the solar system. It’s also more vulnerable to surges, lightning strikes, and ground leakage that could harm appliances.

For Australians, this is where the Clean Energy Council (CEC) comes into play. The CEC has a list of approved inverters (and other components), as well as an army of accredited installers that went through their program.

These CEC-approved transformerless inverters have been checked to ensure safety, reliability, and performance. This protects your appliances as well as the grid. Naturally, the installers know all about these inverters and know how to install them properly, so they pass strict standards.

Oh, and working with a CEC-accredited installer makes you eligible for rebates that lower your upfront cost, too. If you’re not working with one yet, though, don’t worry. We have a network of pre-vetted installers ready to give you 3 FREE quotes right away.

Okay, so what about standard inverters?

Standard inverters are, well, the conventional transformer-based inverters that were typically used back in the day. Think of them as the reliable old trucks of the solar inverter world.

Don’t get me wrong. They’re still used today, but TL inverters are quickly becoming a staple in Australia.

These transformer inverters are heavier, typically more expensive and less efficient than their newer counterparts. The presence of an actual transformer, however, means it achieves galvanic isolation between DC and AC circuits, thus making it the safer choice.

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Which one is better for your home? Standard or transformerless inverters?

As discussed, there are pros and cons for each type of inverter but here’s a recap.

Transformerless inverters are quickly becoming mainstream because they occupy less space, are more efficient, and are more affordable. Efficiency aside, TL inverters are a great option if you’re tight on either money and/or space. Putting high efficiency back into the equation means you also get more solar power to use.

The caveat is that they require a bit more attention to detail to ensure that they’re just as safe as their conventional equivalents.

On that note, transformer inverters are still a strong choice, particularly if you value safety over everything else. Not that a transformerless inverter isn’t safe, but the traditional one is just safer out of the box.

The downside is that they’re larger, cost more money, and aren’t the most efficient components for your solar energy system.


In the grand scheme of solar energy, transformerless inverters are like the smart, sleek smartphones of the bunch—packed with features and efficiency but needing careful handling. Their conventional cousins, with their transformers, are more like the rugged landlines—less about finesse but dependable and straightforward.

Choosing between them? It really boils down to what you value more: the efficiency and compactness of TL inverters or the straightforward, robust nature of traditional ones. Either way, the goal is the same: harnessing the sun’s power to light up our lives. And that, my friends, is something worth chatting about.

But, before you leave, don’t forget about our network of pre-vetted solar installers. We trust them with our own solar systems, and you can, too. Just let us know if you need their help, and we’ll send 3 FREE quotes your way right away.