This article does not go into complex tech details of inverters, but rather offers 10 tips of simple things to consider when choosing the best solar inverter for your home or business.
1 – What type of inverter do you need?
There’s basically two different setups that you can have for your home or business. The first one is a string inverter. The second one is a micro inverter or power optimizer system. Now there is an article on our website that explains this a bit further. But basically, the string inverter means that you’ve got a string of panels connected together, so you may have five or up to about 12 panels connected together in a string configuration. What that means is, if one of those panels in that string is affected by shade, or debris, the whole string of panels is going to be affected by that weakest link. A microinverter or a power optimizer is different in that that the panels will operate completely independently. So if one panel has some shade or some debris, that panel will be affected, but the rest of the panels on that same roof area won’t be.
Image above shows a string inverter install with two panels effected by shade.
Image above shows how microinverters work with the same shading.
You might be thinking, why wouldn’t I just use a micro inverter or a power optimizer for my roof, it seems like a much better thing to do?
Well, price is one consideration. Micro inverters and power optimizers are a lot more expensive than string inverters. Also, you’re gonna have a lot more equipment on your roof. So potentially a lot more points of failure and things to go wrong. So you really want to take a look at your roof and work out if you’ve got a big block available for all your panels to sit on, with very little shade and debris around. If you can find that, a string inverter will probably be the way to go. If you’ve got a roof with lots of different angles and orientations, where you need to put panels in different places, or you’ve got a lot of shade and debris, then a power optimizer or a micro inverter will be the way to go.
2- How long has that company manufacturing the inverters been here in Australia selling their products?
If you look at the CEC list of accredited inverters in Australia over the last decade, you’ll find that the overwhelming majority of them have unfortunately dropped off and are either no longer serving the Australian market or are no longer in business altogether. What that means is there are a lot of orphan solar systems out there. Lots of people who have paid a lot of money for solar systems have inverters now that are unfortunately not working, and don’t have warranties anymore.
Our advice would be to have a look at the manufacturer, find out how long they’ve been trading globally, and then find out how long they’ve been selling here in Australia. And make sure you find somebody that has a really good track record.
3- What is the warranty, and is the manufacturer going to honour it?
So this really fits in with number two. Some inverters will come with a five year warranty, others will come with 10. And some will even come with 12. That being said, when you look at those 10 and 12 year warranties, have a look to see exactly what’s covered because a lot of them will be a five plus five, meaning the first five years is full coverage, the second five years of that full 10 year period will only be parts and labour, or potentially seven years if it’s a 12 year warranty. So have a look at the warranty documentation, make sure the manufacturer is going to be willing to warranty it. And then make sure it’s clear to you what that warranty actually covers over time!
4- Technical data and reviews.
As I said earlier, we’re not going to get into too much complex information here. If you are interested, we have data sheets on our website. Now with the reviews, you have to be very careful where those reviews are coming from, what the sources are and how credible they are. In Australia, there’s lots of “solar experts” out there right now, who more often than not have skin in the game with a particular manufacturer. So their opinions are very biassed. Or sometimes it’s just somebody on a whirlpool forum that has basically very limited information about solar. Maybe they’ve installed the system on their own home and done a little bit of research, landed on a brand and now they’re advising others that that’s what they should use. So check the reviews, but check the source of the review and make sure that it’s coming from somewhere really credible, where you can trust the information that you read in. At GI Energy, we don’t stock any brand of inverters and we can sell and install any inverter on the market, so our reviews are really with your interest in mind.
5- Is your home or business single or three phase?
Now you may not know this -most people don’t- but there’s a very easy way to check whether your house is set up for single phase or three phase power. Go where your meters are read, open the door of your meter box, there’ll be a little switch in there that is usually labelled “main switch”. It will either have one single pole with a switch up and down, or it will have three poles that are connected together in a block to form one switch/lever. If you have one, then you’re single phase power if you have three, you’re three phase power!
Why is this important with an inverter? Well you really want a single phase inverter for a single phase home or business and a three phase inverter for a three phase home or business. A single phase inverter will work with a three phase power setup, but it’s not ideal. So really, you want to make sure that if you have three phase power, you have a three phase inverter, which is going to mean a far more effective solar system.
Some of you might be thinking, Why isn’t this number one, price is obviously very important? And you’re right, it is. But if you base your decision on what solar inverter to install purely based on price, unfortunately, you’re almost certainly going to fall into that category of people who no longer have warranties, and they have faulty inverters in years to come. Bearing in mind that these are 5, 10 or 12 year warranties, you really want your product to stand the test of time. Price is a consideration for everybody, we understand that. But if you base your decision purely on price alone, the likelihood of you being burned is pretty high. That being said, you don’t necessarily have to buy the most expensive inverter either. Obviously, budget needs to be considered. So have a look at the price of the product. But consider those other points first.
In Australia, the solar industry seems to promote a free Wi Fi monitoring as a bit of a buzzword these days. Well, the dirty little secret is that every single inverter that you buy will have Wi Fi capability built in, and it is always free. It’s not an add on. It’s not an addition, and it’s not a unique selling point.
That being said, the monitoring from one inverter to another is very different. And depending on how intricate you want that to be, or the level of monitoring that you want for your home or business, this may be a very important consideration for you. For example, a string inverter typically will only monitor the overall production of your solar system. Whereas with an optimizer or a micro inverter, you’ll be able to monitor individual panels and zoom in on their performance individually to see if one panel is effective more than another that might need some cleaning or some debris coming off or might in fact be faulty and need to be replaced.
In addition to that with your monitoring, usually, a solar inverter and a solar system that you buy will have monitoring that will only monitor the production of your solar system. If you want to monitor how you’re using power in your home, that is nearly always an add on, it’s not usually included in a standard solar setup. You’ll need to purchase another device commonly referred to as a smart meter, which will sit in your switchboard and it will monitor your household consumption, you’ll then be able to see how much solar you’re producing and how much energy you’re using at your home. Which means then you can basically get more out of your solar system by adjusting things.
You may also be thinking, why would I want to monitor my solar system, I don’t have a spare five minutes in the day anyway, I don’t want to be spending my time looking at my solar production. And that’s a very fair point for a lot of people. But if you’ve got your solar monitoring set up, and you programme your email address into the back-end of that platform -which is very easy to do- you never have to look at it. And it will simply send you an email if there’s something there that needs your attention, like a serious fault with an inverter or a massive underperformance issue that’s ultimately going to affect your return on investment.
So the monitoring is a really important aspect of your solar inverter.
8- The location where you are going to put your inverter
There’s a few things to consider here. First and foremost, is your inverter going to be close enough to your home Wi Fi for your monitoring to work? If you put your inverter out of Wi Fi range, it will not communicate and you won’t be able to get the monitoring online. It’s the same as if you have your smartphone in your hand and you wander too far away from your home Wi Fi network, you’ll see the bars disappear, then you’ll no longer have access to a signal. If you’re standing at your inverter location and your phone doesn’t have really strong Wi Fi signal. That probably means that your inverter isn’t going to be capable of communicating with your home Wi Fi.
The other thing with the location of your inverter is some of them are a little bit noisy. So if you’re going to install an inverter outside, close to a bedroom window or close to a working area, and it has a fan cooling system, it is going to make a bit of noise. So just be considerate of that. Some brands have fan cooling, others just have heat sinks to keep inverters cool. So if you’re purchasing one with a fan cooler, be aware that they can make a little bit of noise and make sure that wherever you’re putting it is not going to annoy you over the years.
The last thing with the location of your inverter is the aesthetics. If you’re very house proud, or you’re very particular about how things look (which let’s be honest, a lot of us are) you might want to consider the aesthetics and how the inverter looks if it’s going to be in an area where you’re often socialising with friends. For example, you might not want to see that inverter sitting there on the side of the wall. So consider that prior to the install team coming to your house and make a decision about where you want that inverter to go.
9- Where is the inverter made?
I’m sure that most of you know this already: most inverters are made in China these days. There are still some made in Europe, and some made in other countries, but the majority of them are made in China. That is not a problem as long as you’re choosing a very well established brand that has been selling into Australia for a long time, gets great reviews, and ticks all the other boxes that we’ve talked about. So where it’s made is really going to be a personal preference for you. Typically, the European brands are a little bit more expensive as you could imagine. Sometimes they’re a bit more reliable. So check out where it’s made, and then I guess you’ll need to just gauge your own level of comfort if you are choosing a brand that is made in China versus a brand that is made in a European country.
10- Who is going to install the inverter for you?
It’s all very well going through points one to nine and ticking every single box, finding the right type of inverter with great reviews, fantastic Tech Data, the right type of inverter for your roof with a really long warranty if someone’s going to come along and do a terrible job of installing it for you. So do your research on the people that are actually going to come and put the inverter on your wall and install your solar system and make sure that if you’ve got a great inverter, it’s going to be a great install because one without the other really isn’t much good for the long term.