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Solar Inverter Technology
Solar panels do not work on their own. They are part of a PV system that facilitates solar power conversion into usable energy. One other very essential component of the solar system is the solar inverter. Most people tend to overlook this component, forgetting how crucial it is in the solar system as a whole.
While solar panels produce energy, solar inverters facilitate the use of the energy produced by the panels. It's safe to say that the solar inverters represent the brains of the solar system. Therefore, the better the solar inverter, the better the solar system. Solar inverters do a lot to facilitate the use of the energy produced by solar panels.
As a result, various factors contribute to the efficiency of solar inverters. Factors such as the type of the solar inverter and the size are just but a few factors that determine how a solar inverter works. This article will highlight some of the essential things to know about solar inverters and, most specifically, how solar inverters work. Let's get right into it!
What Is A Solar Inverter?
As indicated earlier, a solar inverter is a solar system component. The solar inverter caters to the conversion of electricity produced by the solar panels. A solar system that lacks a solar inverter cannot operate effectively. This is because the energy absorbed by the solar panels may only be stored in a solar battery but cannot be converted into energy that can be used in the homestead.
There are various types of inverters with different features. Therefore, the type of solar inverter you choose will have an impact on the effectiveness of your solar system and the subsequent energy production in your home.
Due to various technological modifications, solar inverters have been specialised to facilitate multiple functions. For instance, there are certain types of solar inverters that will enable the maximum conversion of energy; others will integrate advanced communication together with monitoring systems to provide you with a great insight into the energy production and use in your home.
Types Of Solar Inverters
There are about six primary types of inverters. This categorisation is based on the solar inverters' distinct features, modifications, and functions. The various categories include:
Micro inverters
In relation to their names, micro-inverters are smaller in size and capacity compared to other types of solar inverters. Micro-inverters are installed at the back of each solar panel and used as an alternative for a single central solar inverter in the entire solar system. These types of inverters are preferred where clouds or shade cover the solar panels because they perform better. However, a primary disadvantage of micro-inverters is that they are pretty expensive.
Hybrid inverters
Although hybrid solar inverters are rare in Australia, they enable you to connect batteries to your solar system. When the solar panels and the batteries use a single inverter, and the solar panels produce direct current (DC) used for charging the batteries through a DC charger, direct current coupling occurs.
The hybrid inverters communicate with the solar batteries through the process of direct current coupling. Hybrid inverters facilitate the regulation, charging, and discharging of solar batteries. One other advantage of hybrid inverters is that they can operate without the installation of a solar battery. They are also cheaper than buying two separate solar inverters. However, they are less efficient.
String inverters
These are the most common types of solar inverters. Every residential unit requires only one string solar inverter. Where a string inverter is used, various solar panels collect solar energy and feed it to a central solar inverter through a series of electrical wires. String inverters are available in most stores and are pocket friendly. However, they are not compatible with solar batteries without the incorporation of an extra battery inverter.
Battery inverters
Battery inverters are effective and preferred by solar enthusiasts. Battery inverters can be used together with solar panels or separately. They specifically facilitate the conversion of DC electricity in a storage unit, say a solar battery, into AC electricity that is best for domestic consumption.
Central inverters
Central inverters are used with equipment that requires a lot of megawatts or kilowatts. They are primarily used commercially for large-scale installations or in utility-scale solar farms. They might not be the top choice for residential units. Central inverters are big and resemble a big metal cabinet, with every cabinet holding about 500kW and above.
Grid-tie inverters
Grid-tie inverters can match the grid electricity wave of the electricity produced to enable the solar system to export electricity to the grid. Therefore, due to this feature, most micro-inverters and hybrid inverters are grid-tie inverters.
Off-grid inverters
These types of inverters are compatible with diesel-generated electricity. They are designed to maintain an off-grid life.
What Is A Solar Inverter Charger?
These are not so distinct from typical solar inverters. The only difference here is that there is a solar inverter with the ability to charge the solar battery continuously. These kinds of solar inverters are helpful during blackouts. Their ability to switch to battery power automatically instead of solar panel power makes them preferable for off-grid energy use. They can thus help in keeping the system operating in the absence of sunlight.
Considerations Before Buying A Solar Inverter?
Since there are different types of inverters varying in size, capacity, quality, and features, it is essential to consider some crucial factors before paying for a solar inverter.
Size of the solar inverter
Every solar panel has a prescribed solar inverter depending on the capacity of the solar panel. To know the size of solar inverter suitable for your solar panel, do not look further than the user manual that comes with your solar panel. There cannot be a better size of solar inverter than the one prescribed by the manufacturer of your solar panel.
Whereas this is the most recommended decision to make, there are certain exceptions that would impact your decision otherwise. Most experts discourage purchasing a solar inverter whose capacity is below your solar panel's capacity. Hence it is recommended to buy a solar inverter whose capacity is slightly above the capacity of your solar panel.
Grid connection
We have seen that there are grid and off-grid types of inverters. As a result, the grid connection becomes an essential consideration before purchasing a solar inverter. Would you want to be connected to a grid or not? Suppose you choose to be connected to a grid. In that case, it is best that you purchase a solar inverter that has an efficiency of at least 95 per cent for transformer less inverters and at least 93 per cent efficiency for transformer-based inverters.
Solar inverter display
The solar inverter display contains the necessary information, such as the installation and operation of the solar inverter. You may also find the information on the general kilowatts of the solar inverter, the daily kilowatts produced by the solar inverter, and the remote-control functions of the solar inverter.
Warranty
Solar inverters have varying warranty durations. Solar inverter warranties depend on factors such as whether the solar inverter will be connected to a grid or not, the type of solar inverter, the size, etc. However, in most cases, solar inverters have warranties ranging from five to twelve years for off-grid solar inverters.
On the other hand, grid-based solar inverters have warranties ranging between ten to twenty years after the date of purchase. Solar inverter warranties offer security and protection for your solar inverters. It is almost like an insurance cover over the solar inverter. The longer the warranty, the longer the protection for your solar inverter.
Weather-proof
Depending on where you will be installing your solar inverter, it is vital to check whether it is weather-proof or not. Weather-proof solar inverters are more convenient for outdoor installations. For solar inverters that are not weather-proof, you will have to purchase a separate protective casing to protect your solar inverter from harsh weather conditions.
Some solar inverter companies offer installation, meaning that they may bring a protective casing with them. However, it is crucial that you ask the company whether you will need to buy a separate protective casing for your solar inverter.
CEC approval
The clean energy regulator keeps a list of all the approved solar inverters in Australia. Therefore, it is best to confirm whether the solar inverter you intend to buy is among the ones included in the CEC-approved list. CEC approval means that the solar inverter is suitable for use in Australia since it will not pose any harm and it will stand the climatic conditions experienced in Australia.
The Function Of A Solar Inverter
A solar panel has photovoltaic cells that are made of semiconductor layers of crystalline silicon or gallium arsenide. The layers are both negative and positive but connected through a junction. Through the photovoltaic cells, solar panels absorb sunlight energy during the day; this energy travels through the negative and positive layers, knocking electrons loose.
This movement leads to the production of direct current electricity that is stored in the solar battery. Similarly, the direct current electricity may be transferred to the solar inverter directly, depending on the type of solar inverter you purchase. Once the direct current electricity reaches the solar inverter, the inverter takes it to a transformer where the energy is converted to alternate current from direct current electricity.
Besides the transformer, other devices such as the power transistor and the MOSFETs (metal-oxide-semiconductor field-effect transistors) help transfer the energy into the primary side of the transformer. The changing voltages at the optional winding in the primary side of the transformer lead to the production of an alternating current. The transformer also expands the voltage ratio from a standard of 12 volts to 120 or 240 volts, which is suitable for use in homes.
Solar inverters can also communicate with your home computer to notify you of the amount of energy supplied by the solar panel and the amount of energy used by your home appliances. This is also to protect the energy grid from harmful over-voltage. In that regard, if an overvoltage occurs, the solar inverter will shut down the entire solar system, thus preventing the transfer of the over-voltage to the grid.
Current technology provides solar inverters with new features and, thus, new functions. For instance, modern solar inverters are designed with a monitoring system that enables the user to keep track of the solar system's performance. This further allows you to keep track of the energy supplied, thus allowing you to identify any shortages in energy production. Similarly, most modern solar inverters come with a remote-control system that enables you to put the inverter to rest manually.
How Much Is A Solar Inverter?
In general, there is no one price for a solar inverter. Depending on the size, quality, and other inverter features, the price ranges from about $1,000 to $2,000. There are additional costs, such as the cost of installation, which ranges from about $150 to $300.
You may incur some discounts if you purchase the solar inverter together with the other components of the solar system. However, there are usually no discounts when you are replacing a solar inverter. Therefore, it is best to choose a solar inverter that will last and save you the replacement expenses.
Choose The Right Solar Company
If you're looking to get a solar inverter, it is vital to work with experts. Solar power system installations are best handled by professional solar installers who can advise on the most suitable inverter for your solar panels. Better yet, these services can all be combined in one to save you the stress of multiple installations and buying components from different places.
It is also essential to get a solar inverter with features that suit your needs so you do not have to replace your inverter every now and then. With regular use, a solar inverter that does not have the right features to match your energy use will lose its efficiency quickly.