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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.
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!
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.
A visualization of how we plan where inverters are connectedIn the market, these are the 3 basic types of inverters to be aware of:
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 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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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 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.
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!
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.
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!
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Solar panels generate a type of electricity known as direct current or DC.
However, this isn’t the kind of electricity typically used by household appliances.
This is where a solar inverter plays a crucial role.
The inverter takes the DC electricity from the solar panels and transforms it into alternating current (AC), the form of electricity needed to power your home’s appliances.
However, the role of solar inverters extends beyond just converting electricity.
They are also instrumental in enhancing the efficiency of your solar power system, ensuring you get the maximum possible energy output.
Additionally, inverters contribute to the safety of your solar setup.
They monitor for electrical irregularities and detect power outages from the utility grid.
This capability is vital for protecting your solar panels, your home, and utility workers from potential electrical hazards.
In this guide, we will learn about how to pick the right solar inverter for your home solar system.
This process involves understanding your household’s average energy consumption, gauging the potential output of your chosen solar panels, and ensuring that all components, particularly the inverter, are suitably matched in capacity.
When selecting an inverter for your solar panel system, it’s crucial to match the inverter’s input voltage and current requirements with the specifications of your solar panels.
For instance, if your solar panels have a maximum output voltage of 350V, you need an inverter that can operate effectively within this voltage range.
Let’s say your solar panel array features an open-circuit voltage (Voc) of 400V and a maximum power point (Vmpp) of 350V.
In this scenario, you should opt for an inverter whose maximum input voltage can safely exceed 400V.
This ensures it can handle the panels’ Voc without any issues.
Additionally, the inverter’s MPP voltage range should be around 350V to align with your panels’ optimal operating voltage.
By carefully matching these specifications, you can ensure efficient and safe operation of your solar power system.
When setting up your solar power system, the inverter’s power rating is a key factor to keep in mind.
This rating determines the maximum power load the inverter can manage, thereby defining the potential output of your system.
For example, if your solar panels can produce up to 6kW at their peak during sunny conditions, you’d typically need an inverter rated at least 6kW to fully utilize this output.
However, opting for an inverter with a much higher rating than your panels’ peak output isn’t always the best approach, especially if you’re considering future expansion.
Industry norms often suggest choosing an inverter rated for about 75-90% of your solar panels’ peak power.
For instance, for a 10kW solar panel array, an inverter rated between 7.5kW and 9kW is often more appropriate than one rated exactly at 10kW or higher.
This sizing strategy, known as ‘inverter clipping,’ is based on the understanding that solar panels rarely reach their peak output due to factors like shading or the sun’s angle.
By using an appropriately sized inverter, you can enhance your system’s efficiency and avoid the extra cost of an oversized unit.
A too-large inverter might not be as efficient at lower power levels and could lead to unnecessary expenses.
However, it’s crucial to strike a balance.
An undersizing inverter can limit your system’s output.
Consulting a professional to determine the ideal power rating for your inverter, considering your specific solar array size and whether inverter clipping is suitable, is a wise decision.
String Inverters: Best for large, unshaded areas. They are cost-effective but less efficient under partial shading. Top brand: Fronius, SMA.
Microinverters: Ideal for roofs with shading or different orientations. They optimize each panel’s output but are more expensive. Top brands: Enphase.
Power Optimizers: Suitable for partially shaded areas, offering some benefits of microinverters but at a lower cost. Top brands: SolarEdge.
Hybrid Inverters: Great if you plan to use battery storage. They can work both on-grid and off-grid. Top brands: Outback
Central Inverters: These solar inverter types are often used for large commercial installations and standalone inverters for off-grid setups
Efficiency is a key aspect of any solar inverter, playing a vital role in the overall performance of your solar energy system.
Look for inverters with high-efficiency ratings (usually 95% or more).
Higher efficiency means more of the solar power is converted into usable electricity.
Currently, some of the top players in the market, like SMA, boast conversion efficiencies exceeding 98%, while leading micro inverters from brands like Omnik offer efficiencies up to 96.5%.
Solar inverters are frequently installed outside buildings, where they are exposed to varying weather conditions.
Therefore, it’s essential to ensure that the inverter you choose is robustly built to withstand these environmental factors.
When selecting an outdoor inverter, look for one with a durable casing or technology designed to operate reliably under unexpected weather conditions.
It’s important to remember that temperature variations can significantly affect your photovoltaic (PV) system’s performance.
High temperatures can increase the system’s voltage, potentially pushing it beyond the inverter’s maximum voltage specification.
This could lead to damage or, in severe cases, cause the inverter to fail.
Conversely, in cold conditions, the system’s voltage might drop too low, causing the inverter to shut down.
A key feature to look for is an inverter with IP65 technology, which offers a level of protection against harsh weather conditions.
Inverters with this specification are designed to resist dust and water ingress, ensuring they can operate effectively even in challenging environments.
Making sure your inverter has such protective features can save you from frequent maintenance or replacement costs and ensure consistent performance of your solar energy system.
Your inverter acts as the central command center or “brain” of your solar panel system.
Equipped with the right software, it plays a crucial role in continuously gathering information about your home’s energy usage and the electricity output from your solar panels.
Most manufacturers develop dedicated apps, allowing you to easily access and monitor this data.
Advanced inverter software often includes additional features.
These might enable you to manage your power loads more effectively, navigate time-of-use rates to save on energy costs, and record your energy data.
This can be particularly helpful in forecasting your monthly energy bills and identifying further opportunities for savings.
In essence, the more control and interaction you have with your solar panel system, the more benefits you can reap.
However, it’s important to note that these apps are not perfect.
Some solar monitoring apps may have technical issues and might not consistently provide real-time updates on your solar system’s performance.
A good way to gauge the reliability and user experience of a specific solar app is by reading through user reviews in app stores.
These reviews can offer valuable insights into what you can expect in terms of functionality and usability when using the app.
In the solar industry, while there are some globally recognized brands, you’ll often encounter lesser-known names.
When you come across a brand you’re not familiar with, it’s a good idea to do thorough online research.
Start by checking their rankings on Google or other major search engines.
But don’t stop there. Dive into various sources like news articles, blogs, forums, comments, and customer reviews to gauge public opinion about these brands.
This feedback can be incredibly insightful.
Positive mentions and experiences shared by others can be a green light to explore more about these brands, possibly leading to a purchase.
Additionally, factor in the cost. It’s important to balance affordability with quality.
Remember, the cheapest option isn’t always the best in the long run, especially when it comes to crucial components of a solar power system.
Assess the value offered by each brand in relation to their price to make an informed decision.