Differences Between A Transformerless Solar Hybrid Inverter & A Transformer-Based Non-Hybrid Inverter: Pros & Cons, Which Is Better & When It Can Be Used Best

With the soaring cost of electricity bills, having only a solar energy backup is just one step in the quest for true power sufficiency and independence. Hybrid inverters, though having been in existence for many years, have become more sophisticated in not only doing the basic function of a regular inverter (charging the batteries and supplying electricity from the batteries for usage), but also in helping users save on electricity bills.

However, don’t be quick to discard your long-time transformer-based inverter; the heavy-duty power conversion house has served you diligently throughout these years, and even still, its office is still very much needed even in these times.

In this article, we will explain the differences between the modern intelligent hybrid inverters and the conventional transformer-based inverters. We will also be looking at their advantages and disadvantages, and the conditions that might necessitate what you might choose, so that you will have all the knowledge you need to make the best decision.

We also made a detailed user-focused comparison between these two types of inverters (transformerless hybrid inverter and transformer-based non-hybrid inverter) in this video:

What Is A Transformer-Based Inverter

Simply put, transformer-based inverters are those inverters that have an inbuilt transformer that converts DC power to AC power that can be used by appliances. Though some special ones, like the Luminous 1.5kva solar hybrid inverter, have inbuilt solar charge controllers, generally, most do not have the solar charging function built into them.

They were the type of inverters mostly used in most solar installations in the past and come in various voltages: 12v, 24v, 48v, 96, 180v, 360v, depending on the size of the system.

Advantages

1. Stronger: Transformer-based inverters are very strong due to their transformer and general design. It tolerates electrical surges and overloads better than the hybrid inverters and is best for industrial and other heavy-duty appliances with inductive loads and high start-up currents.
   
2. Better Handling: These types of inverters handle adverse conditions such as low, high, or fluctuating currents better and are also less sensitive to electrical noise and errors.
   
3. Durability: A transformer-based inverter can last for many years, and many have been working for more than 20 years.

Disadvantges

1. Solar Maximization: The major disadvantage of a typical transformer-based inverter when compared to a hybrid inverter is its inability to intelligently utilize power from the sun, grid, and battery, at the same time, to give the user the maximum savings on the electricity bill.
   
2. Efficiency: These types of inverters are less efficient, especially at lower loads, than hybrid inverters because of their bulky components and transformer, which results in higher energy conversion loss.
   
3. Cost: A solar system that was set up using a conventional transformer-based inverter will have its own separate solar charge controller. This usually results in an increased overall cost of installation.
   
4. Limited Battery Compatibility: Many of these types of inverters are not compatible with lithium batteries because they do not have a specialized battery management system (BMS).

Transformerless Hybrid Inverters

These are the next-gen type of inverters that make use of high DC voltages without the presence of the bulky transformer; voltage step up and down all happen electronically. What makes an inverter hybrid is its ability to intelligently combine power directly from the sun and any shortfall taken from the national power supply grid or batteries, depending on the user settings, and feed it directly to the house.

So let’s say the load in the house is 2000 watts, and the early morning sun is only giving 500 watts. The hybrid inverter will take the 500w from the sun and take the balance of 1,500w from either the grid or battery to power the appliances. When the input from the sun increases to 1,500w, the hybrid inverter will take that plus the balance of 500w from the PHCN grid to power the home directly.

Some of these types of hybrid inverters, collectively known as grid-tie inverters, enable what is called net-metering, where applicable. This is where excess power generated from the sun is sent to the grid to offset electricity units used.

These types of inverters have an inbuilt solar charge controller, usually MPPT, for higher efficiency, are more techy, and are compatible with lithium batteries.

Advantages

1. Return on Investment: Solar hybrid inverters have a faster return on investment by helping users save on their electricity bills by combining solar energy input with electricity from the grid or battery in real time.
   
2. Advanced Technology: Modern hybrid inverters come with advanced tech such as Bluetooth and wifi for remote monitoring. This can be used by both the homeowners and the solar energy company to track performance and usage.
   
3. Higher efficiency: Transformerless hybrid inverters provide about 95% to 99% efficiency across a wide range of loads, unlike transformer-based inverters that range from 85% to 95%. This is true due to its lighter components that draw less power.
   
4. Light Weight: Transformerless hybrid inverters are significantly lighter in weight when compared to transformer-based inverters simply because of the absence of a transformer and other bulky internal components.
   
5. Aesthetic appeal: Modern hybrid inverters come with better design and screens that provide better user interface, unlike their traditional counterparts that communicate mostly with illuminated icon lights and sounds.
   
6. Battery Compatibility: Modern hybrid inverters have an advanced battery management system (BMS), which makes them compatible with a wide range of batteries such as AGM, flooded (tubular), and lithium.
   
7. Cost: With the influx of numerous direct Chinese manufacturers, hybrid inverters are currently cheaper to buy compared to the traditional transformer-based inverters, which are mostly produced in India.

Disadvantages

1. Less rugged: Transformerless hybrid inverters generally cannot tolerate surges in electrical demand above their recommended band, as well as transformer-based inverters. This surge in electrical load, be it the start-up load in heavy-duty appliances like air conditioners, or simply mistakenly going above the maximum output of the inverter, for example, when a pressing iron that was unplanned for gets used, can lead to its failure. Hence, extra care must be taken to calculate the intended total load.
   
2. Protection: Great care must be taken in the installation of hybrid inverters because they are generally more fragile. Good AC & DC surge protectors, grounding, and breakers must be used to protect the inverter from extreme currents and surges.
   
3. Less Durable: Hybrid inverters have more electrical parts and advanced techs which increases their chance for failure.
   
4. Downtime from Solar Failure: The solar panels are connected directly to the hybrid inverter, so if there is a failure with the solar component of the inverter, the inverter will be removed for repairs, and the user will be stranded, unlike transformer inverters, where only the solar charge controller will be removed.

Where It Might Be Best To Use Either The Traditional Transformer-Based Inverter Or The Hybrid Inverter

Having discussed the pros and cons of both the solar hybrid inverter and transformer inverters, there exist certain conditions that might necessitate the type that a potential user might go for.

1. Clean electrical supply: If the customer’s electrical setup is not clean and there are instances of poor electrical installations in the building, then it is best to have the transformer-based inverter installed because it can handle these conditions better. However, it is of utmost importance that the electrical issue is resolved.
   
2. Type of Load: If the user wants the solar setup to power heavy-duty appliances like machinery, it is best to have the transformer-based inverter installed.
   
3. Return on Investment: While this is the ultimate goal for installing solar in the first place, the hybrid inverter is the winner here.

Transformer-Based Inverter Vs Hybrid Inverter: Which Is Better

In conclusion, there is no clear-cut winner between the traditional transformer-based inverter and its intelligent hybrid counterpart. The choice depends on the needs of the user; however, in recent times, the solar hybrid inverter is more popular and is mostly the go-to.

For basic use in homes and offices, the transformerless hybrid inverter is more suitable, while the transformer-based inverter is best for heavy-duty use and in other situations where the conditions do not seem perfect.