A lot goes on behind the scenes of setting up a solar system at your place. Right from the selection of the right type of panels, to selecting an inverter and then finally aligning it with your current power system – many choices are to be made. Let us walk you through a quick guide to buying the best solar inverter for your place. In layman terms, a solar inverter helps transform solar energy into usable electrical energy for your business.
Why do you need solar inverters?
A solar inverter (also known as Photo Voltaic inverter) converts the Direct Current (DC) output of solar panels into Alternating Current (AC) that is supplied to your building or can be fed to the grid for usage. The solar inverter also adjusts the voltage requirements of the load. Between the solar panels and the load, there are Balance of Systems (BOS) components situated for smooth transitioning. The main components are Solar Battery Storage, Inverter & Charge Controller.
Let us understand more about solar inverters used to generate housing and using commercial solar power in detail.
What are the different types of solar inverters?
Ø Grid-Tied Inverters: These types of inverters work with Grid-tied solar systems, which are connected to the grid power integrally. The inverter converts DC to AC. Using a bidirectional interface; the power generated from the systems is fed to the grid or building at the distribution panels. Works great for Net Metering Purposes. Here the excess power generated can be supplied back to the grid! This earns you a feed-in tariff (credit) from DISCOMS (distribution companies). However, this system does not have a battery backup. The inverter stops functioning in case of power failure known as anti-islanding. The safety feature ensures that no power is supplied back from the solar system.
Ø Off-Grid Inverters: Best for remote locations where you are not connected to the power supply grid. The best solar inverters are used with off-grid solar power systems that are completely disconnected from the power grid. They function like normal power inverters and current AC to DC (for necessary power backup). In case of grid failure, it converts the stored DC to usable Alternating Current for consumption.
Ø Hybrid or Grid-Interactive Inverters: These battery reader inverters are a combination of solar and battery inverters packaged in a single unit. They also provide a basic power backup in case of power failure. These inverters are now becoming more appealing as the batteries are becoming cheaper and the hybrid inverter technology is advancing.
Ø String Solar Inverters: The solar panels are stringed together with parallel connections. The power goes to a centralized inverter that converts DC from the solar panels to AC. Though the inverter is cost-effective, it produces comparatively less electricity.
Central inverters convert the DC power received from each string into Alternating Current for seamless consumption. With the help of Micro-Inverters, you can measure the performance of every single panel in the system. These are installed for individual solar systems and convert DC power into AC.
There are multiple inverter options available in the market for using commercial solar power at your workplace. All you need to do is figure out your budget, the space you have for installing these inverters and your solar panels and solar battery storage.
What are the rating criteria for buying the best solar inverters?
1) The Capacity
The maximum load that you can connect to the inverter determines the capacity of the inverter. Now, depending on the amount of commercial solar power you require you can decide the capacity of your inverter and get one installed.
2) Battery Capacity
The solar battery storage capacity gives you a fair estimate of how much the solar inverter can offload. And also, the amount of load that can be supported during a power outage. An important factor to consider while buying a solar inverter.
3) Check the Surge Power
Your inverter will have to power ratings – peak power and usual power. Peak or surge power is the maximum power the inverter supplies for a short amount of time – to start a heavy appliance which then runs on regular (typical) power after the initial boost. And, the usual power is what the inverter steadily supplies to all the appliances connected to it. Leads to continuous rating.
4) Check the metering support
This will help you determine if the inverter supports net metering facilities with Utility (Net) Meter Integration.
5) Understanding how Power Maximization works
Maximum Power Point Technology (MPPT) tracks and then optimizes the solar panels to find the maximum PowerPoint which helps to get the best output from your solar panels. The power produces by the panels depends on several factors like shading, temperature (do not let your panels get heated, it affects their output), and irradiance levels among other factors. MPPT helps you find the energy hotspot.
6) Monitoring the energy output
The best solar inverters come with monitor systems via display panels or mobile apps that help you track the energy output. This will help you understand how well your panels are working in different conditions, and then you can make the required changes accordingly.
Things to keep in mind while buying a solar inverter for your workplace
- Check if the inverter complies with the Australian Standard set by the Clean Energy Council
Let’s be honest, you don’t want to get stuck in a bureaucratic mess when all you wanted to do was switch to green power and invest in the best solar inverter. Now, the first thing to keep in mind while shopping for the solar inverter is referring to the list of approved products by the Clean Energy Council. The inverter must comply with the relevant Australian Standard (AS4777) and you are good to go!
Also, if you are looking for a lucrative solar subsidy from the government, then your solar power system must be manufactured of components that agree with the compliance standards. Read more about the compliance systems, and also check the manufacturer of the solar inverter to see how long they have been in business and their certifications.
- The budget you have in mind for installing the best solar inverter for your workplace
Technically, grid-connected inverters are a part of the solar power system package. So, if you plan on buying the components individually for the most optimum combination, then you need to do solid research on your part. This will help you get a solar inverter at the best prices. For an estimate, an inverter should cost you about 20% of your total budget.
The most popular type of inverter – 5kW can cost around $1000 for starters. They can also accept 6.6kW solar panels. If you are looking at a 3-phase 5kW inverter then there will be an additional cost of about $400.
Avoid buying cheap inverters as they definitely won’t last you 15 years long. Avoid buying a bottom-range product so that it can survive the tough conditions down here in Australia. Make the right choices.
- Check whether the solar inverter is sturdy and weather-proof
We were just discussing how difficult it is for inverters to last 15 years, given Australia’s climate conditions. It would help if the inverter is weather-proof. Now, most of the inverters are weatherproof–IP65 rated so that they can survive in an area that will expose them to the elements. Your inverter is composed of sensitive electronic items that wouldn’t survive the heat or excessive exposure to harsh weather, and so it is important to invest in one that is secured already. Also, look into insurance options for your system set-up just to be on the safer side of things.
- Look into the warranty period of the inverter
On a general note, solar inverters have a lifespan that ranges between 10-20 years. They are low maintenance and require just the basic clean-up every once in a while. So, you are looking at 10 years of good quality service and ROI. The warranties on solar inverters range between 5 to 12 years, depending on the type of inverter you buy. There are also 5+5 year offers where parts and labour are covered in the first half, and then only the parts in the second half of the warranty period. You must ask important questions about the long-term upkeep of your solar inverters. Make the investment last.
- Now decide the best inverter capacity (size) for your workplace
We have already discussed how capacity will affect your inverters functioning and also the costs.
The basic rule of thumb would be to ensure that your inverter can handle at least the maximum power your panels generate. This means if you have a 5kW solar power system then your panels will have to be 5kW and the inverter too. But a word of caution, the inverters are rated about 25% less in AC kW as compared to the solar panel array. This is because of AC-DC conversion metrics.
The Clean Energy Council has specific guidelines which will help you determine what type of undersized inverters you can work with. We suggest that you do your research. Also, inverters are rated in DC Input & AC Output terms, so make sure that the DC output of your solar panel is being matched by the inverter’s input capacity.
- Do you plan on adding extra solar panels to your system at some point?
The retailer will offer you larger solar inverters in case you plan on expanding your system at some point. Just make sure that you have enough space on your roof for the upgrade before you already invest in one. Then there’s also the possibility of your panels going out of the market as the technology keeps on changing. Check MMPT or multi-string solar inverters that help you build an optimal solar power system.
Connecting multiple solar panels and buying an inverter that can handle them might be the best way to build your solar power system but all of this depends on your budget and space availability.
Also, consider the size of the inverters. Small string inverters are the size of a large briefcase. And larger ones are the size of a small travel case. Make sure you place the inverter in shade (they do not need contact with sunlight) and are close to the electricity meter. Many factors to consider before you make the purchase.
- Is your solar inverter expandable?
And by this we mean, if it can handle additional solar panels installed in the future. You can use an MPPT inverter or microinverters that not only help expand your solar panel system but also calculate the individual outputs of the panels. Just in case the new panels differ from the old module? That is covered too!
Yes, that’s all you need to keep in mind (at least) before finalizing a solar inverter for your place!
You can look at your current energy requirement and see what type of energy generation you are looking for from your solar inverter and then make the purchase. The amount of energy generated (Kw hours) and the electricity consumed (Kw hours) should match.
We wish you all the best with your system upgrade and to a green-power switch!