As you start to research on solar panel systems, you might start to wonder what solar inverters exactly are. In this article, we’ll take a deep dive to unravel the mystery behind them, and shed light on their crucial role in solar panel systems. Whether you’re a budding solar panel enthusiast or just curious about sustainable technologies, join us as we explore what solar inverters are and why they are essential components to a greener, solar powered world.
What Exactly Are Solar Inverters And Why Are They Important?
To understand what solar inverters are, we first have understand the different types of electricity currents.
There are 2 types of electricity currents, namely alternating currents and direct currents. What solar panels produce are direct currents (DC), whereby electricity only flows in one direction. However, what powers your house are alternating currents (AC), which flow in both directions. As a result, what your solar panels produce cannot be used to power your house.
This is why we need solar inverters – they basically act as a middleman between your solar panels and your home. By converting direct currents produced from your solar panels to alternating currents, your solar panel system will be able to power your household!
How Are Solar Inverters Connected Within Your Home?
Your solar inverter should be located at a place which is both wall-mounted and in a well-ventilated area, shielded from rain and direct sunlight.
The DC output cables of your solar panels will first be combined and run to your inverter. You can choose to either place it near your attic balcony area, or near your DB box located on the ground floor. Most will choose to install them near their attic balcony area as it prevents cable loss between the solar panels and the inverters, which could lead to a drop in efficiency.
After which, the AC output of the inverter is connected to your distribution box (DB). Any excess electricity generated will then be sold back to the grid through metering credit schemes.
Types Of Solar Inverters
In the market, these are the 3 basic types of inverters to be aware of:
On-grid inverters
As the name suggests, on-grid (also known as grid-tied) inverters are inverters which are connected to the grid. On-grid inverters also allow you to sell excess electricity generated by your solar panel systems back to the grid, helping you net greater cost savings. During the night, or when your solar panel system is down, these inverters draw electricity from the grid instead to power your house. This is where you can explore electricity plans that cover off-peak periods, further maximising savings on your electricity bills.
In countries such as Singapore where electricity grids are generally stable and metering credit schemes are readily available, on-grid inverters are highly recommended.
For us, we use the Huawei SUN2000 inverter, which has one of the highest efficiencies in the market at 98.6%.
Off-grid inverters
Off-grid inverters are inverters that contain their own batteries, allowing them to operate independently off the grid. How off-grid inverters work is that excess energy generated from your solar panels will be stored temporarily within the batteries of the off-grid inverters. This stored energy is then expended at night, or when the solar panel system is no longer producing energy.
These types of inverters are generally recommended in more rural areas, where electricity from the grid might be less consistent and stable. In Singapore, where battery costs are expensive and grid electricity is already very consistent, it is not recommended to get an off-grid inverter.
Hybrid inverters
Offering the best of both worlds, hybrid inverters contain both batteries to store excess electricity & are also connected to the grid. The main benefit of a hybrid inverter is in its ability to store energy that can be used to take advantage of varying electricity rates throughout the day.
However, hybrid inverters are generally not recommended in Singapore as they do come at a steeper price because of the battery cost as well.
Considerations When Choosing Solar Inverters
When it comes to choosing solar inverters, solar inverters already come in a package with your solar panel system. Therefore, choosing a solar inverter is generally not needed as you can just follow your solar installer’s recommendation, who has a clearer idea on which inverter is the most compatible for your system.
However, it is still good to know what constitutes a good solar inverter for your solar panel system, as shown below.
System size and capacity
Relative to your solar panel system, you would ideally want your solar inverter to have a capacity that matches or exceeds the total output of your solar panels. This capacity is typically measured in kilowatts or watts.
This is primarily to avoid inverter clipping, where your inverter is unable to convert excess DC generated from your solar panels to AC due to a limit in its capacity.
However, in situations where your solar panel system is larger than average, your installer might suggest an inverter which is slighly smaller in capacity than your solar array. This is because based on pre-calculations, it would be highly unlikely for your solar panel system to reach its maximum output, hence it would be more cost efficient to get a smaller inverter.
Efficiency and conversion rates
Typically, an inverter’s efficiency will fall between 93% to 99% as it would always require some of the input DC power to run itself. To increase efficiency of your solar inverter, you ideally want a solar inverter that is integrated with Maximum Power Point Tracking (MPPT) technology. MPPT is basically an algorithm which helps to extract maximum available power from your solar panel system under suboptimal conditions, such as hazy, dark or cloudy days. How it does that is that MPPT will take into consideration multiple factors, such as light levels, shading, temperature & more, and attempt to extract the most amount of power.
Single-phase vs 3 phase
Whether your house runs on a single-phase or a 3-phase meter also affects what kind of inverter you can install in your home. If your house runs on a single-phase meter, which has limited power capacity compared to a 3-phase meter, you would require multiple inverters of smaller voltages compared to using a single large inverter, which prevents grid overloading.
While this may come at an additional cost & take longer to set up, having multiple inverters is not entirely a disadvantage. In the event one of the inverters breaks down, you are still able to leverage other inverters in the system to draw electricity from your panels.
Durability and warranty
Inverters typically last around 10 to 12 years, and have a warranty period of 5 to 10 years, depending on how pricey the inverter is itself. Some brands also offer extended warranty options for additional costs if you wish to explore that possibility, but this is provided that you are certain you do not wish to install additional solar panels on your roof in the future or have already maximized your roof space, which will alter your total solar panel capacity.
Maximizing solar output
If you are a homeowner looking to maximise your current solar panel output, you might also want to look into whether your solar panel system is affected by shading. If your solar panel system is connected to a string inverter, you can consider purchasing power optimizers to accommodate for parts affected by shading. Beyond this, there are also other ways to maximise your solar panel output in Singapore, which you can read more here as well.
Monitoring and data capabilities
You also want to look for inverters that offer advanced monitoring features. Some inverters come with built-in monitoring systems or can be connected to external monitoring platforms, allowing you to track your system’s performance and detect issues promptly. Examples of this include Huawei’s FusionSolar app, which instantly alerts you on issues with your solar panel system such as abnormal solar panel temperatures, partial shading and even malfunctioning solar panels.
Internal Cooling Systems
A common complaint amongst some solar homeowners is that inverters might produce humming or buzzing noises which may be annoying or disrupting. These noises are primarily produced because of the inverter’s fans which help to prevent overheating. If you do see this as a potential issue, you can consider getting inverters with internal cooling systems instead of fans, which are generally quieter and less disruptive in nature.
Common Issues with Solar Inverters
Just like everything else, there may also be times where your solar inverter might run into performance issues. When these occur, the first course of action should be to always contact your solar installer or technician, and avoid attempting to troubleshoot the problem yourself.
Overheating
When installed in places exposed to direct sunlight or poor ventilation, there is a high chance that your solar inverter may overheat. This can also occur if proper maintenance is not done, which could lead to loose connections or dusty systems. When overheating occurs, you can consider turning off all non-essential electrical appliances to reduce the load on your inverter.
Isolation faults
Isolation faults can also occur to your inverter, which would cause your inverter to shutdown. These occur when the isolation barrier between the inverter’s internal circuit and the grid degrades, which causes an unintentional electrical connection between the inverter’s internal components and the grid.
Worried about maintenance?
If you are considering installing a solar panel system yourself but are concerned over the maintenance required to be done for both your system and your inverter, you might want to look into zero upfront cost rent-to-own options. Rent-To-Own allows you to pay fixed monthly fees to install your very own solar panel system, with professional servicing & maintenance , ensuring a 100% worry-free solar experience.
To find out more about Rent-To-Own solar in Singapore, click here!
Can I DIY The Installation Of My Solar Inverter?
In the context of Singapore, DIY installation of your solar inverter is illegal and is strictly not allowed. Installing a solar inverter requires direct access to your roof, and this requires proper safety equipment which is not accessible to the average homeowner. Beyond this, testing and commissioning of your solar panel system also has to be conducted by licensed electricity workers from SP, so the possibility of installing solar inverters by yourself is not possible.
Conclusion
Solar inverters are a crucial part of your solar panel system and are the crux to ensuring your whole solar panel system runs smoothly together with your home’s electrical system. Hence, it is of utmost importance to ensure your solar panel system is paired with a high quality inverter to meet the needs of your system.
Are you still in the midst of considering whether to get your first solar panel system? At GetSolar, we have developed a free instant solar simulator to help you gauge how much you can potentially save with solar and how much it costs, with just a single click of a button. Click here to get your free quote today!
