Who are they?
If you’re looking into solar energy, then you’ve probably heard of Fronius. They’re the most popular inverter in Australia, and an installers favourite. Why? Let’s find out…
First, a bit of history. Fronius began way back in 1945 in a small Austrian (not Australian) village, where Günter Fronius started a battery charger company. That’s right – for 75 years Fronius have been involved in electricity generation and storage. They’ve been in solar since 1992; longer than most popular solar panel manufacturers. Fronius International truly are one of the grandfathers of the industry.
Fronius inverters first came to Australia in the 2000s – and it went terribly for them. Being a European brand, their inverters weren’t designed for the heat and humidity of the Australia, with ensuing failures. However, unlike other companies who may have given up or run away, Fronius delved into analysing every failure and fixing the causes. Furthermore, they serviced every warranty. Nowadays Fronius make one of the most reliable and loved inverters – in part because they’re still manufactured in Austria or Czechia (Czech Republic), unlike most, which are made in China.
What do they do?
Fronius have four product lines: the Galvo and Primo, for single-phase households; the Symo, for three-phase buildings; and Eco, for large three-phase installations.
The Fronius Galvo are all less than 3kW, so for tiny systems. They’re so small I won’t even bother discussing them right now – you’ll want at least 3 🙂
The Fronius Primo comes in 3.0, 3.5, 3.6, 4.0, 5.0, 6.0, and 8.2kW sizes. Quite a few! The 5kW is by far the most popular right now, as it allows for unlimited export (see Export Control) and lets you have a 6.6kW system. The Primo 8.2 lets you go up to a 11kW system.
The Fronius Symo has an even larger range in sizes: 3.0, 3.7, 4.5, 5.0, 6.0, 7.0, 8.2, 10.0, 12.5, 15.0, 17.5, and 20.0kW! Now, given that the Symo is for three-phase supplies, it’s uncommon to use the small ones; at GI Energy we find the Symo 10kW and 15kW to be the most popular, allowing for 13.3 and 20kW systems, with 20kW being the next most popular, into which you can connect a 26kW system.
Apart from the phases and power sizes, the Primo and Symo are similar. They’re 98% efficient and have two MPPTs (except the small Symos), allowing for two strings of panels – for example an East-West roof split.
The last is the Fronius Eco. There are only two sizes, 25.0 and 27.0kW, which are you only Fronius option if you want a system over 30kW on a single inverter. Also 98% efficient, but it only has 1 MPPT, making it much less flexible when it comes to system design. For this reason, it’s often better to use multiple Symo inverters instead of a single Eco inverter, unless a perfect single-string layout can be designed for your system. It’s not uncommon to use four Symo 20s for a 99.9kW system. (Why not 100kW? See STCs)
Why are they good?
Temperature Control
A key feature of Fronius inverters is the built-in fan. If you know anything about electronics, you know electronics do not like heat. Every computer has a fan, for this reason. Heat causes solder to melt, resistance to increase, and generally leads to inefficiencies and electronic death. Even though inverters must not be installed in direct sunlight, ambient temperature and operating itself can cause inverters to get very hot. Fronius have overcome this issue by installing a fan, to keep the inverter running cool and efficiently. You’ll often find a Fronius will run cooler than other competing brands, extending lifespan and efficiency. The one downside of this is the added noise of the fan, which can make Fronius inverters significantly louder than others; that said, it’s unlikely (and not recommended) to install the inverter in a living or sleeping area, so the noise shouldn’t cause a disturbance. Compared to other inverters, they’re also a little heavier (again, the fan), but they’re a similar size.
Monitoring: Solar.web & Fronius Smart Meter
Fronius provide free Wi-Fi monitoring with all their inverters. Simply connect your inverter to your home Wi-Fi, and the inverter will send your data to the cloud for you to view on your phone or computer. This service is called Solar.web (yes, with the dot). By default, it only shows solar production, although with the addition of a Fronius Smart Meter you can also view your consumption, and hence the difference between the two.
The Dashboard gives an overview of your system.
The upper-left Current Power chart is a real-time animated display of your energy. The solar energy flows to the inverter, and from there it either flows to your house, the grid, your battery (if you have one), or a combination of the three. Easy way to see where your energy is going! If your house is using more than your solar power system generates, energy flows from the grid. Note that if you don’t have a Smart Meter it will show all production going to the grid.
The middle Energy Balance chart shows the difference between what you’ve generated and what you’ve used – green (above the horizontal line) is when you use less than you generate, which is where you want to be! Note that if you don’t have a Smart Meter it will just show production in grey.
The upper-right Earning chart guesstimates how much money you’ve saved (based on how much you’ve generated and exported), and also how great you are for the environment – how much CO2 you’ve saved compared with traditional energy generation, also displayed as car distance and trees planted.
Clicking Energy Balance in the top menu takes you to a slightly different version of the chart on the Dashboard, with consumption and production on the same chart. As you can see, Matt’s system is wonderful – it covers all his day-time consumption (the dark grey that looks a bit like Batman) and still exports plenty to the grid (the green above), saving him money and earning him more! This is because, by using his Smart Meter to monitor his usage, he’s been able to use timers and other specialised devices to ensure his power usage happens during the day, when his solar panels are generating. Note that (surprise!) if you don’t have a Smart Meter it will just show production in grey.
Like how your computer or phone may have software updates, to remove bugs, increase security, and improve performance, so too do Fronius inverters! These can be applied via a USB stick, although if you have the Fronius Smart Meter they can be done remotely – much easier.
The final thing the Fronius Smart Meter allows is export control, which is mandatory for certain systems (see our article on Export Control for more info).
Warranty
Fronius offer a “5+5” warranty; you automatically get 5 years of Plus warranty, and if you register your inverter online (for free) you get an extra 5 years of standard warranty. The standard warranty covers the cost of materials to repair the inverter; the Plus also includes transport and labour costs (i.e. zero out-of-pocket expenses). This can be extended up to 20 years by purchasing Warranty Extension Plus. And to make things even easier, Fronius have an office in Melbourne, so if you have any issues, they’re easy to get hold of.
Conclusion
Fronius are certainly a premium product, as reflected by the price. However, you do get your money’s worth; an established and reliable company, manufactured to high standards, with products for every situation. It’s not surprising they’re one of, if not the, top-selling inverter in Australia.
Written by James Gibbins, our in-house Engineer who has completed a Master’s degree in Electrical and Electronics Engineering.
