What are the different types of solar inverters on the market?

With all the conversation around solar installations, it can be easy to get caught up in some decision-making complications that make it difficult to move forward. Thankfully, some foundational knowledge on the different types of solar inverters can go a long way.

Let’s discuss the most common options and their benefits. 

There are four main types of solar inverters:

1. Hybrid Inverter

Hybrid inverters are smart inverters with the ability to store excess solar energy in a battery system for back-up purposes. Direct Current (DC) flows from the solar panels to the inverter, where it is converted to Alternating Current (AC) or stored as DC in a solar battery. The converted AC power can be used to power household appliances, where the excess can be fed into the grid. 

 

They are able to function in several different modes based on the application they are being used for at the time, including battery back-up mode, which provides some back-up power in the event of a power cut. A hybrid inverter can also function without a battery and export excess solar energy to Eskom’s utility grid. 

 

Hybrid inverters combine the features of off-grid and grid-tie inverters into one useful device and eliminate the need for a separate inverter for any battery bank connection. 

1. Off-Grid Inverter

An off-grid inverter is a solar inverter that is not connected to mains/Eskom power at all. The off-grid solar inverter draws power from a battery, where it converts the DC power to AC power. They do not sync with the electricity grid, and so they also cannot feed excess production into the utility grid either. This means that all excess energy must be stored in batteries, so the battery pack needs to be large enough for this purpose. 

 

They must supply power from DC to AC quicker than other inverters, so they need intelligent processing power to be able to react quickly.

 

Off-grid systems are completely energy self-sufficient, so they will not be affected by power outages on the utility grid. 

1. Grid-Tied Inverter

Grid-tied inverters are designed to supplement mains power, not replace it. Where sufficient solar power is available, it is delivered to the system through the standard DC to AC conversion process. However, when conditions do not allow for sufficient solar power to be produced, such as on cloudy days or at night, the system will switch back to grid power alone. 

 

These inverters are also able to feed excess solar power, which has been converted from DC to AC, directly into the grid. They synchronise with the grid, both in output voltage and frequency, so they are able to put power into the grid as any excesses are produced. 

1. 3-Phase Inverter

A 3-phase solar inverter converts DC power generated from the system’s solar panels to AC power. However, the output distribution is across a 3-phase power supply, not the usual single-phase supply commonly found in households. 

Features of the most sought-after Hybrid Solar Inverter

Hybrid solar inverters are the most sought after solar inverter, as they are incredibly useful in a number of different ways. Because they can store excess solar power in a battery pack, they can be used around the clock, regardless of grid availability and weather conditions. They can also be used at nighttime, when solar energy is unavailable. 

 

They can be used to allow for more efficient use of the grid, as they can be programmed to switch on during peak hours, when electricity is the most expensive. They can therefore be used for cost savings, and this also allows for a quicker return-on-investment on the cost of installing the solar system. 

 

These inverters have a number of benefits that make them so popular. 

• Effortless power consumption monitoring

An intelligent metering device is an important part of a hybrid solar inverter, eliminating the need for frequent load calculations, which can be time consuming and introduce the possibility for error. This allows for the user to know exactly how much power is consumed by the connections, making managing the load much simpler and more efficient. 

 

Because a hybrid inverter can be installed without a battery, they can be used to determine the future battery requirements of the system. 

• Latest Technology

Since hybrid inverters blend power from all available sources through the use of smart technology, they use all of the available solar power generated by the solar system more efficiently. This provides a much more rounded energy supply.

• Multiple MPPT inputs

Most hybrid inverters have at least two MPPT inputs, as well as a high voltage range. To explain this further, it will be helpful to understand the definition of an array. An array is a collection of solar panels that produce power as a system. More MPPT inputs means that a wider array can be connected, allowing for greater energy generation capacity. It also allows for separate arrays to be connected, so if one array fails, the other array will still be available as a back-up. 

• Scalable

Hybrid inverters can be connected in parallel. This means that the system can be scaled up in capacity in the future, since more can be added. Hybrid inverters can communicate with most lithium-ion batteries, which can also be connected in parallel. Having a PV system that is able to grow with increasing energy requirements is an incredible feature in the long-term, making these inverters very desirable. 

• Flexible

Non-essential loads can also be powered with a hybrid inverter if energy production exceeds the essential load requirements. This means that a PV system with a hybrid inverter will not be as constrained by its essential load settings, as any extra power that is produced can be used to power non-essential appliances. 

• Ability to blend power from multiple sources

Battery power and power from the electricity grid can be used to power the connected load in conjunction with the power generated from the solar arrays. Because of this, no matter the conditions of the grid or the weather, chances are that there will be sufficient stored energy to power appliances for quite some time. 

• Efficient

Because of the intelligent technology used in the design of most hybrid inverters, as well as their ability to blend power from multiple sources, hybrid inverters are much more efficient. This is because they can switch between energy sources, allowing for energy storage and cost savings to be maximised. 

• Easy to install

Hybrid inverters simplify the installation process, as the connection requirements are greatly reduced by their increased functionality. For example, since hybrid inverters do not require an additional inverter for a battery connection, the installation is slightly more simple. However, all solar installations should ideally be done by a professional to prevent any safety or warranty issues. 

• Long-lasting

A quality, well-maintained hybrid inverter can last about 15 years or more. 

Features of Off-Grid Inverters that are a popular cost-effective choice.

Off-grid inverters are perfect for when a grid connection is either unnecessary, unlikely, or unwanted. These inverters are useful for those looking to become completely energy self-sufficient, such as those in remote areas. Off-grid inverters can also be set up on boats, camper vans, and other mobile setups. 

 

Here are some benefits of off-grid inverters: 

• Expandable

Like hybrid inverters, off-grid inverters can also be connected in parallel, allowing for an off-grid solar system to be scaled up should electricity requirements increase. 

• High or low voltage

Because there are two main types of off-grid inverter (high or low voltage), the inverter can be chosen based on how many solar panels will be connected. This allows for the size of the inverter to be chosen based on the size of the PV array. A smaller off-grid system can thus be designed to power the essentials. 

• Easy to install

Because off-grid inverters are not connected to the grid, and therefore do not need additional features such as grid syncing, small off-grid systems have this reduced complication. However, as mentioned previously, it is best to get an inverter professionally installed to prevent any safety or warranty issues. Larger off-grid systems built to power bigger operations can be a lot more complicated, so this is also something to keep in mind. 

 

Grid-Tied Inverters feed back to the grid and are grid-dependent for power.

Grid-tied inverters are designed to function with the electricity grid to save money. They are very useful where back-up functionality is not required. 

 

Here are some important aspects to note about grid-tied inverters:

• Grid connection required

A grid-tie inverter cannot function as a back-up system, as it is designed to supplement the mains utility with solar power. These inverters synchronise solar and grid power to reduce utility bills quite drastically, and can even be used as a source of side income where excess energy is produced to feed into the grid, so these inverters are very economical. However, it is important to note that they will not work in the event of a power failure. 

• Solar Panels required

A grid-tie solar inverter must be connected to a solar array, as this is the power source used to supplement grid power. 

• Scalable

Like hybrid and off-grid inverters, grid-tied inverters can be connected in parallel to scale up a solar system’s capacity. 

• No Batteries required

Because grid-tie inverters do not have back-up functionality, there is no need for a battery installation. Since batteries are often the most expensive part of a PV installation, this reduces the overall cost significantly. 

• Energy metre installation

It will be essential to ensure that an energy metre is installed before a grid-tie inverter is considered, as power will flow into the municipal grid through the electricity metre. This allows for accurate readings to be taken on the property’s energy consumption and supply. 

• Ideal for daytime peak usage

Because peak hours have the highest rates, a grid-tie inverter set to function during peak daytime hours can reduce electricity costs significantly. 

A 3-phase power supply would require a 3-phase solar inverter.

In electricity, the phase refers to the electricity load distribution of Alternating Current (AC). Single-phase power has a two-wire power circuit, with one power wire and one neutral wire. 3-Phase power has a 3-wire power circuit to accommodate higher loads. While single-phase supplies are commonplace in households, 3-phase supplies will generally be found in commercial and industrial buildings. 

 

It is very important to note that any property with a 3-phase electricity connection will require a 3-phase inverter, or three single-phase inverters connected in parallel. This is because a single-phase inverter will not be able to handle the load requirements of a 3-phase setup. 

 

Although all the choices available may seem complicated, it is important to start from the beginning. Knowing your requirements and budget will prove incredibly helpful when deciding on which inverter to purchase, as the features and benefits of each type of inverter can be compared against these criteria. 

For more advice on choosing the correct inverter, reach out to Battery Power-Zone here. Alternatively, visit the Battery Power-Zone website and browse the list of quality inverters on our online store today.