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Microinverters are a critical part of a solar panel system. Their principal role is to convert your solar panels' direct current (DC) energy into usable AC or alternating current electricity for your home or business. They help ensure that you get maximum power from your solar system more effectively. This article provides more information on microinverters. Simply read on to find out.
What Are Microinverters?
Microinverters are small gadgets that are installed at the solar panel site. Solar panels using micro-inverters use a single microinverter for each panel. Each of these gadgets works at the panel site independently of the others in the panel system. The microinverters are classified as module-level power electronics or MLPEs.
These are usually the most effective option for complicated installations or those that experience marginal shading. With the conventional string inverter technology, solar panels only generate electricity at the lowest-performing solar panel level on a similar string.
This problem does not arise with microinverters since the solar panels have their own inverter. The panels will continuously perform efficiently even if a single panel in the system fails to generate electricity. The right size of solar inverters is determined by the solar panel's size and the amount of electricity it generates depending on the tilt, geography, and direction the panel is facing.
Clipping will occur when the solar panels generate more electricity than the microinverter can convert at a specific moment, which leads to power losses.
When Should You Use Solar Microinverters?
There are many instances in which you can install solar microinverters in your home or business. Microinverters make it easy to monitor individual panel performance in your solar panel system. Microinverters allow you to compare the performance of each panel on its own instead of tracking the performance of the entire system.
This leads to faster servicing of the equipment because you can quickly determine if the microinverter or a particular panel is failing. Microinverters offer the best solution for more complex installations with solar panels facing different directions or tilting at different angles.
For instance, if you have some solar panels that face east and others south, using microinverters in every solar panel allows them to perform to their maximum ability. They are also not affected by the power generation issues that other solar panels face.
One of the things to note is that microinverters are usually costlier than other options. However, the extra upfront cost is worth it since the gadgets help monitor and improve energy generation production benefits.
How Do Microinverters Work?
Each solar panel connected in the parallel grid usually works independently with a microinverter. Thus, the microinverter converts the solar energy generated by one solar panel from DC to AC electricity. Modern microinverters use maximum power point tracking (MPPT) and other advanced ways to maximise every panel's solar power in your business or home for better optimisation.
Then, the AC electricity gets into your property after the inversion to run all your appliances and cool or heat your business or home.
Microinverters Vs. Other Inverters
The most significant distinction between microinverters and string inverters is that with string inverters, you use strings to link your solar panels. These strings are then connected to one inverter. On the other hand, microinverters link each panel with its individual inverter.
Depending on your solar system's size, you should only use single or two-string inverters. This makes it easy to troubleshoot your system if it has an issue because all the panels the inverter supports are usually wired to just a single destination. With the minimal wiring needed, string inverters are less costly to install and maintain than microinverters.
However, the simple wired scheme can make it costly to expand the size of your solar system without purchasing a new inverter in the future. This also means that if a single solar panel is not working, it affects the entire circuit instead of its single output.
Power optimisers do not change direct current (DC) into alternating current (AC), unlike string inverters and microinverters. They usually condition the DC and send it to the centralised inverter. They are module-level power electronics that work similarly to microinverters since they evaluate single solar panel performance. Power optimisers provide flexibility in creating a solar system on a partially shaded roof.
Evaluation Of Microinverters
As you compare the microinverter options, here are some significant considerations to make.
Level of efficiency
Like solar panels, microinverters also vary in terms of efficiency. The efficiency of a microinverter is measured by the amount of energy lost in the form of heat as it converts electricity from DC to AC. Microinverters with high-level efficiency usually translate to high overall system efficiency and higher solar electricity generation.
Microinverters are available in different sizes. Each of them is designed to hold different electricity voltages. The larger options are costlier, but you should not install a smaller microinverter than the required energy output as it could lead to too much clipping. Luckily, manufacturers of solar microinverters usually have a guideline on the maximum wattage that solar panels need when connected to their products.
In most cases, microinverters come with a 25-year warranty. This helps protect you against manufacturing issues or underperformance. But it is also advisable to consider that two manufacturers with similar terms of the warranty may provide varying levels of coverage as part of the warranty provided.
As a result, it is always important to read and compare the warranty agreements as you choose the correct solar equipment for your home or business needs in Australia.
Cost of the microinverter
Even though they are not the costliest component of a solar system installation, you still need to consider the price you pay for a microinverter. Microinverters with high-level efficiency are costlier. However, they are worth your money depending on your home's solar powering needs.
Rapid shutdown requirements
The National Electrical Code (NEC) establishes an immediate shutdown requirement for solar panel systems. Put simply; a rapid shutdown allows you to de-energise a rooftop solar panel system quickly.
Microinverters with a rapid shutdown usually automatically shut down to comply. Each module features programmed software to shut down in sync with the rapid shutdowns. In this case, you don't need any other hardware.
Benefits Of Microinverters
Investing in microinverters offers you a lot of benefits. Below are some of the inverters' advantages to your solar panel system.
Microinverters get attached to the mounting kit under each of the solar panels. The inverter is usually designed using high-tech electronics to change DC to AC under each panel. This makes it possible for each panel to output power without depending on the other panels leading to increased system output.
Enhanced flexibility of the devices
It is easy to create a panel array across several roof areas with microinverters across different angles and orientations. If you utilise some of the power in the afternoon, it helps the solar panels facing west and north to allow the distribution of energy throughout the day.
This helps avoid high peak moments of solar power during midday time. With this, you can use or store a significant percentage of the solar power in your solar batteries as it is produced, thus increasing your system's value.
Increased solar system safety
Micro inverters are made to convert DC to AC power immediately under the solar panels, also known as AC solar panels. They usually help prevent the need for high voltage DC cables leading to increased safety in your home. With solar fires becoming standard in most homes using DC systems, the conversion to AC helps avoid these fires.
It's also good to note that power leakage occurs mainly on longer DC cable runs. AC cables usually run long distances without any risk of power leakage, making Enphase microinverters a great investment to enhance your overall property's safety.
No one point of fire
If something malfunctions with one of the microinverters or solar panels, the other part of the system that is yet to be affected will remain operational. With this, you get less downtime, making it possible for you to continue generating solar energy during service checks and warranty claims.
Easy to expand
The other great thing about microinverters is that they are easy to expand. You can install as many solar panels as you want. This makes microinverters an excellent investment for your home or business.
Microinverters allow the solar panels to work at their optimal potential depending on shading, weather conditions, and many other factors. This ensures that a single panel cannot affect the entire system's performance. With a central inverter, all the solar panels are treated as a single giant panel featuring all the electrical properties of one unit that is not performing well.
Besides, with a centralised design, all the solar panels are usually oriented the same way, but at times when it is not possible, uniform orientation does not lead to the maximum output for all the solar panels.
Allow for panel-level monitoring
Microinverters feature a standard monitoring service to allow you to see the amount of power being generated at any time at each solar panel level. With these details, you can understand how your solar system is performing and make a more informed decision on your home's or business' energy use.
Require small cable size
The conversion of DC to AC is done at the back of the solar panel system. Thus, the cable needed for carrying the current is smaller than those required in centralised solar panels.
No air cooling needed
Microinverters are small in size and fit effectively in your panel's back. With their small size, you don't have to invest in a separate cooling system as cooling happens with central inverters. There is also less loss of heat in your home with microinverters.
Disadvantages Of Microinverters
Here are some of the disadvantages to know about microinverters before buying them.
High upfront cost
Microinverters are viewed as premium devices, billed at a higher price. They are costlier than centralised inverters because they require more labour costs, advanced cabling, etc. Thus, you end up paying more for microinverters than centralised converters. However, as you compare the costs of other alternative systems to microinverters, focus more on full ownership costs rather than the upfront costs.
Require higher-level maintenance
When microinverters fail, your contractor has to go up the roof and remove the solar panels to access the microinverter. This is unlike the central converters mounted near the primary electrical supply.
This makes the servicing and installation work easier than that of microinverters. In addition, it is hard to replace microinverters because of existing site conditions, and the job necessitates more than one technician.
Not suitable for battery backup system
One crucial thing to note is that solar batteries are the future of solar energy. This is because they allow for better energy storage generated from the sun to use at a later time. Microinverters are home batteries ready, meaning that you can add to your solar system any time you need them with no extra equipment required.
However, if you want to add battery storage to your system, microinverters are unsuitable. To get maximum power output, you need to couple your solar panels to your battery before changing electricity to AC and back to DC.
How To Choose The Best Microinverters For You
To gain all the above benefits of using microinverters, it is essential to ensure that you get the best one that will meet all your solar system needs. Below are some of the significant factors to put in mind.
Consider the input voltage
One factor to think about when investing in microinverters is the input voltage. The input voltage selection should be well-coordinated with the inverter's power. This is the case because, with increased output power, the input currents also increase, making it hard for the transistors of the output stage.
This also leads to significant energy loss on the connecting wires. As a result, you need to choose a microinverter with a higher input voltage.
The peak and nominal output power
The rated output power of a microinverter should be the same as all loads' powers. But, in reality, you need to make the selection depending on the load that has the maximum power. So, you need to think about the starting current of the entire load.
At times it can go up to ten times higher than the actual operating ones, especially for devices such as pumps and refrigerators. If the manufacturer does not show the peak output power, you need to know that the one indicated as nominal is usually the peak output power.
The microinverter's weight
One indication of the quality of microinverters is their weight. Lightweight models are usually of low quality since they feature a transformer-less circuit that can fail when the load gets switched on as a result of large transient currents.
The efficiency of microinverters determines the amount of energy that is wasted. Modern ones come with an efficiency of around 90 to 95 per cent. If a microinverter has efficiency below 90 per cent, then it means that ten per cent of the energy is wasted. This is not acceptable since every watt is very important.
No-load power consumption and stand by
The no-load power consumption of a microinverter should be around one per cent of the rated power. With a rated power of 600W, the no-load consumption should be around 6W. If you are not turning the microinverter off after every use, you should select a model featuring the lowest consumption in the standby mode.
This ensures that minimum energy is spent on maintaining the system. Get a microinverter with a standby mode to ensure that the consumption is minimised significantly.
Check for an empower switch system
An empower switch is critical because it helps isolate your property when there is a power outage. It allows your microinverter to continue supplying power to your property even in the daytime.
The cost of microinverters
As mentioned above, microinverters are smaller string inverters but costlier. Thus, they add to the price of your entire solar system. The price is also high since there are several of them, and they require professional installation and maintenance.
Before investing in microinverters, you need to consider the advantages mentioned above and the disadvantages to determine if they are worth the high cost you will incur. You should think about your needs, situation, and budget.
How To Maintain Microinverters
Microinverters are susceptible to failing more than any other solar system component because of their intrinsic nature. A microinverter performs several tasks and utilises software that needs frequent updating and sometimes gets errors. A suitable inverter lasts for about ten to fifteen years but can also last as long as the solar panel. This makes them a fantastic investment for your home energy needs.
Like other components of your solar system, it is essential to maintain and take care of the microinverters. Your microinverter will last for about 25 years with proper maintenance and installation. This also helps delay buying another inverter and avoid emergencies in your home or business. Here are some of the ways to maintain your microinverters:
Ensure the right installation
For optimal performance, the first thing you should do is ensure that the microinverter is installed correctly. The good thing is that they are simple to install. All that needs to be done is plug them into the solar panels, and they start working immediately. Make sure that the inverter doesn't get in contact with moisture. Allow the installation to be done by a professional to avoid any mishaps.
Microinverters start converting DC to AC immediately after the installation. You don't need to interfere with them, but regular dusting is essential to improve their performance. Wipe your microinverters regularly to remove dust and any other dirt build-up. It is also advisable to leave the cleaning to a professional who understands how to do the job perfectly.
Check the display for errors
Microinverters feature displays that allow for easy monitoring. It's essential to check the display regularly to check out if there are errors that must be fixed. If you find an issue, you should contact your solar system manufacturer to immediately interpret and fix the error. It is also essential to check the modules after hails or storms for any issues that require fixing by your professional.
Buy A Microinverter From The Best Company
Microinverters are fantastic devices that help maximise the energy generated by all your solar panels and convert the power instantly to AC electricity. They are great since they also free your wall space because you no longer need a separate inverter.
Therefore, if you have limited roof space with several angles and have shade or a chimney, microinverters offer the best solution since you do not have to alter your solar panel system. However, you also need to understand that they come with extra upfront costs.
For the best microinverters that will work perfectly for your solar system, you need to buy them from the best solar companies in Australia. A reliable solar professional can provide you with high-quality microinverters and installation and ensure that they are working correctly.