There are over 800 solar inverters on the Clean Energy Council approved product list. How do you whittle this list down to find the best solar inverter for your home?
This blog post helps you do just that!
We start by explaining what a solar inverter is – and why it’s the most important part of your solar power system. We run through the four main types of residential solar inverters, explaining the differences. Finally, we provide a checklist of the ten most important selection criteria to help you select the right solar inverter for your home.
On this blog:
- What is a solar inverter?
- Choosing the right type of solar inverter for your roof
- Ten most important selection criteria
What is a solar inverter?
A solar inverter is a box of electronics – about the size of a briefcase – that converts DC (direct current) electricity from solar panels into usable AC (alternating current) electricity. It is usually fixed to an outside wall or installed in the carport or shed. If possible, it should be located as close as possible to your switchboard and be well-protected from the weather.
A lot of people think that the solar panels are the most important part of a solar power system. But, in actual fact, it’s the solar inverter that determines how well your solar system works. Investing in a quality solar inverter will pay off over the long term, with more power output and less hassle – not to mention improved safety.
Choose the right type of solar inverter for your roof
Before delving into the top 10 criteria for selecting the best solar inverter for your home, it’s important to decide what type of inverter you need. There are four main options for residential solar power systems:
- String inverters – the standard choice for most homes with the widest product selection
- Microinverters – good if your roof is partially shaded
- Power optimizers with string inverter – another (lower cost) solution for partial shading
- Hybrid inverters – a single unit to connect solar panels and a battery
If you have an unshaded roof without any complicated gabling etc., a string inverter is probably the best type of solar inverter for your needs. There are a huge range of string inverters on the market and, as a result, they can be the most cost-effective solution. Goodwe string inverters are a great choice if you’re looking for performance and value, with good Australian support.
Microinverters are excellent solar technology but they are at least 20 per cent more expensive than string inverters. If you have a partial shading issue, power optimizers with a string inverter will be more cost effective and provide similar benefits.
If you’re planning to install a battery at the same time as solar panels, a hybrid inverter could be the best fit for your requirements and work out cheaper all-up. Some hybrid inverters provide a lot more scope for system expansion which might be worth considering if you’re thinking of switching off the gas and going all-electric – and preparing for EV charging from home.
Ten most important selection criteria
- Is it approved for use in Australia?
The starting point is to check that the solar inverter is compliant with the relevant Australian Standard (AS4777). You can do this by checking the approved solar inverter product list on the Clean Energy Council website.
- It is eligible for government rebates?
With generous government rebates for solar power systems worth thousands of dollars, you don’t want to miss out! You need to ensure the solar inverter (and solar panels) you choose for your home are eligible for all the applicable rebates. Make sure your inverter is on the Clean Energy Council approved product list and, if you are in Victoria, on the Solar Homes approved product list.
- Warranty – how good is it?
A good solar inverter should have a comprehensive product warranty for at least 10 years covering parts and labour. Cheaper inverters often come with a five-year warranty – we recommend avoiding those ones! Some quality inverters like Fronius come with a 5+5 year warranty where the first five years are covered for parts and labour but the second five years only covers you for parts. Ideally you want a solar inverter warranty that covers you for both – for as long as possible.
- Manufacturer – do they have a good Australian support office?
A warranty is only as good as the company behind it. You want to make sure that the inverter manufacturer has an Australian office with a technical support team. You’ll also want to make sure that the manufacturer has been in business for at least ten years, ideally longer.
- How efficient is it?
Solar inverters should have an efficiency rating of at least 95 per cent; the best ones will be rated at around 99 per cent efficiency. What this rating tells you is the percentage of DC electricity from your solar panels that will be converted to AC electricity for use in your home. The higher the efficiency, the more solar electricity you’ll be able to generate – which ultimately translates into bigger bill savings.
- Is it weatherproof?
Any solar inverter worth its salt will have a IP65 weatherproof rating. Check it on the datasheet and don’t go anywhere near any inverter that doesn’t have this rating. You also need to check with your installer that the inverter won’t be in direct sun (avoid a north facing wall at all costs!). If there’s any doubt, make sure the installer puts a shade cover over it.
- How safe is it?
Solar system safety [link to blog on this topic] is of paramount importance. With high voltage electricity involved with any solar panel installation, you want to be sure that the system installed on your home meets and exceeds Australian safety standards. Different types of solar panel systems have different safety features so talk to us if you want to be sure you’re getting the safest solar power system for your home.
- Does it have a display?
Some solar inverters have a digital display which shows how much solar power is being generated. These displays can be helpful but require a bit of fiddling around to scroll through the various options. You also need to walk outside and make a conscious effort to look at the display – something you might do initially but perhaps not so much once the novelty has worn off.
- What’s the online monitoring like?
In our opinion, getting good online monitoring is far more useful than a digital display (assuming you have an internet connection and you’re comfortable using a computer or an app).
All modern inverters provide basic solar generation monitoring. But taking it to the next level – by getting consumption monitoring [link to Solar Analytics blog post] – will provide you with far richer insight into how you use electricity in your home.
Some solar inverters have excellent consumption monitoring as standard – but most don’t. Talk to us if this is of interest.
- Is it expandable?
Right now, you may think that a 6.6kW or even a 10kW solar system is big enough for your home. But what if your lifestyle changes? What if you decide to switch over from gas to all-electric? What if you decide to get an electric car – or even two?
In any of these situations, you’ll probably be wanting more solar panels and possibly a battery. So, the question is, will the system you get today allow for expansion down the track?
Some solar inverters like SolarEdge [link to post] are designed to provide huge amounts of expansion, even allowing you to add solar panels that are different sizes and wattages. But most solar inverters are more limiting and won’t let you scale up.
Getting the right advice is important. If you want a solar system that gives you the option to add lots more panels in a few years, let us know and we’ll be able to advise on the best solar inverter technology to meet your needs.
Get in touch
If you’d like advice on the best solar inverter for your home, get in touch. We stock a wide range of the leading brand solar inverters and, as one of Australia’s largest solar companies, we have the in-house expertise to make sure you get the best system for your home and budget.