Fronius Gen24 Review: A Solar Installer’s Considered Opinion

Today I’m reviewing the Fronius Gen24 inverter – Fronius’ latest solar inverter – which supersedes their wildly popular and ever-dependable SnapINverter range in Australia.

Based on my experience in the field, I’ll be looking at the pros and cons and the technical specifications to help you decide if the Gen24 is the right fit for your own solar energy system.

From its modular design to its active cooling system and innovative backup power supply, the Fronius Gen24 has a lot to offer. But is it worth the investment? After all, it’s at least $700 more than some other good solar inverter options.

Let’s find out.

Overview of the Fronius Gen24

Arguably a reassuringly expensive solution, the Gen 24 is a fairly new device, and I suspect it will further cement Fronius’ market leadership down under. These inverters are a good, solid first-world solution, and despite what the haters of fan noise say, the Fronius Gen24 has active cooling for a very good reason: the more heat you remove from the power electronics, the longer they will last — an important feature in our sunburnt country.

The Fronius Gen24 is also an order of magnitude quieter than the previous models.

Beautifully executed Gen24 with 8-cell stack. Credit to Jae Taylor at Joondalup Electrical Services

Design and Sustainability Features

The Gen24 has been designed with sustainability from the outset, and I’m not just talking about how they refuse to pack it in polystyrene. The modular nature of what’s under the cover means your service technician can replace parts in the field without shipping the whole unit to Fronius for repairs. I’ve done it myself with earlier models, and it’s a great way to save time, money and energy, especially when the Fronius technical support service is so good. I’ve mentioned it before, but it’s worth repeating that having support on the phone for commissioning and warranty is priceless. But don’t take my word on Fronius Australia’s support and service; just read all the happy Fronius reviews from Australian consumers.

Fronius Monitoring App Is Good And Getting Better

Fronius also has SolarWeb, a great free app for monitoring production and consumption. But if you want some of the extra features, you’ll need to pay a $33 per year subscription. The most useful ‘premium’ features are:

  • Unlimited history – instead of just three days
  • Return on investment data
  • PV production forecast

The new PV production forecast uses satellite weather data with a 100m resolution to tell you what your solar production should be for the rest of the day. Currently, it only looks forwards, but they have all the weather data to look backwards. If they simply add a ‘looking backwards’ feature in the SolarWeb app, they could show you what your energy production should have been versus what it was, helping consumers see how well their system is performing and if it’s time for a service – similar to the pricier Solar Analytics monitoring service. Although if you do want the whizz-bang Solar Analytics monitoring – their cloud monitoring is directly compatible with the Fronius Inverter’s external smart meter.

Backup Without A Battery – Albeit Very Limited

I’m not sure anyone else has a basic backup power supply without a battery. Fronius calls it “PV Point”; if there’s enough sunshine, you can charge your phone or run other modest devices from a dedicated emergency powerpoint. 3kW is actually pretty good (i.e. 12amps), and even though the solar irradiance might vary, the Fronius will deliver as much electricity as there is daylight to power it.

Gen 24 Solar Inverter Can Upgrade To Batteries

Of course, if you want a comprehensive full backup emergency power supply, then you can pay for a firmware upgrade, add a BYD battery and some control gear in the switchboard, then Gen24 will deliver a pretty gutsy output for a single phase or a three-phase supply. (though the small three-phase units don’t offer full backup) Firmware to control a battery costs between $650 – $1000; the smaller the inverter size, the lower the price.

Bear in mind that – unlike most other hybrid inverter manufacturers – Fronius don’t provide a pre-built ‘backup box’, so you’ll need a good sparky who can do all the backup wiring themselves – essentially making their own backup box from scratch:

3 phase backup of a Gen 24 will typically need 12 ‘poles’ of space in your main switchboard but doesn’t require a separate cable run for the essential circuit out of the inverter, saving on cable and losses. This example is 20 poles. Credit to Jae Taylor at Joondalup Electrical Services

For example, the 6kW single-phase machine (Primo) will deliver just that, plus a surge rating of 8.2kW for 5 seconds. The three-phase 10kW variant (Symo) delivers a nominal 16amps or 3.68kW per phase and a surge of 12.4kW total (4.1 per Phase). However, to get these numbers, you must have enough battery capacity stacked up behind them.

Two classes of batteries are available, and each can be in several different sizes. Bear in mind that some can be expanded more than others. If you need extra storage later, they’ll scale incrementally to 35 or 68kWh.

The actual max. sizes can vary per inverter, but in general it’s as below:

The Gen24 Will Raise Your Frequency In A Blackout

When running off grid the Gen24 will boost the supply frequency to 53Hz to deliberately bump other energy sources off the system. This can make clocks run fast and give your coffee machine a headache. It also means that only one Gen24 will operate in backup mode unless you do some mildly tricky wiring. They will, however, talk to the same monitoring platform, so if you already have a Fronius system, they will appear on Fronius Solarweb together. The warranty is void if you run off-grid for more than 20% of the time.

20-Second Switchover Time

The other complaint/feature of the Gen24 is that when the grid does fail, it takes up to 90 seconds for the inverter to fire up in off-grid mode. Like SolarEdge and some others, this is a safety function to ensure the grid is really gone. While it might seem painful, it’s also an unmissable analogue warning signal, so you can turn things off to preserve your battery. The specified ‘up to’ ninety seconds does seem like an inordinately long time, though. Fronius has recently assured me that the latest firmware update has that down to 20 or 30 seconds, but that’s still quite a wait compared to the SolarEdge battery’s three seconds.

Fronius Ecosystem and Energy Management

The last point I’ll make for Fronius is that they have an ecosystem of other devices, such as the Ohmpilot for hot water and the Wattpilot for car charging, but not only that, they have open communication protocols and relay contacts to drive third-party devices. I have set up a “sunshine circuit” to run a hot water service with surplus solar using programmable priorities to manage energy flows. It works well.

Warranty and Battery Life Considerations

All in all, it’s a pretty solid choice. Fronius offer 5+5 years warranty, which I’ve used before, and the procedure is good. If you are considering adding a BYD battery, the BYD warranty specifies it’ll retain 60% of its usable energy for ten years, or 3Mwh throughput per kWh installed. All is well and good, but the issue with this figure is that if you use the battery’s full capacity daily, you won’t reach ten years.

So 42690kWh ÷ 13.8kW nominal = 3093 days or 8½ years

Or 42690kWh ÷ 10years ÷ 365days = 11.69kWh/day

In the real world, where you may not fully charge or fully discharge the battery daily, then 11.69kWh is probably realistic, but technically, the warranty only scores 8.5 out of 10 from the judges.

Fronius Gen24: Technical Specs

Fronius Gen24 ‘Primo’, Single-phase inverters are available in 3 to 6kW versions. The ‘Symo’ three-phase inverters are available in 3 to 10kW versions.

These are the specs for a typical system: a single-phase 6kW system paired with a 13.8kWh BYD battery:

  • Nominal capacity: 6kW
  • Surge rating: 8.2kW
  • Solar capacity: 9kW
  • PV current ratings: 22 & 12amp nominal – 33 & 18amp short circuit – A and B input respectively
  • Inverter Warranty: 5 + 5 years
  • Battery: BYD
  • Usable Capacity: 13.8 kWh
  • Warranty: 10 years – 60% remaining capacity – 42.69MWh throughput
  • Throughput limit @ 1 full cycle per day: 8 ½ years
  • Approx retail: $3950 inverter $11367 battery = $15317+ installation
  • $-per-usable-kWh: $1110
  • $-per-warranted-kWh :$0.358 @ 1 cycle per day / $0.179 @ 2 cycles per day
  • Three-phase option available with different specifications

Summing Up, My Fronius Gen24 Review: It’s One Of The Best

The Fronius Gen24 hybrid solar inverter is a high-quality, relatively high-priced solar inverter that can be upgraded to handle batteries anytime. Boasting impressive features such as a modular design, active cooling, good monitoring and PV Point for basic backup power supply without a battery, it’s a reliable choice for your solar power system. The compatibility with BYD batteries and integration with other Fronius devices and third-party products makes it a versatile option.

If you are using the Fronius Gen 24 with the recommended BYD battery, it’s important to remember the BYD battery’s warranty limitations and the long delay when switching to off-grid mode. Also, your sparky will need to build their own ‘backup box’ as Fronius don’t supply a pre-built one. Despite these minor drawbacks, the Fronius Gen24 remains a solid and well-rounded choice for those looking to invest in a solar or hybrid solar inverter system. With a reputation for quality, the Fronius Gen24 is my top choice for Australians who want a reliable, high-performance solar or hybrid inverter.

And according to our 2023 poll, it’s lots of other installers’ favourite solar inverter too:

About Anthony Bennett

Anthony joined the SolarQuotes team in 2022. He’s a licensed electrician, builder, roofer and solar installer who for 14 years did jobs all over SA - residential, commercial, on-grid and off-grid. A true enthusiast with a skillset the typical solar installer might not have, his blogs are typically deep dives that draw on his decades of experience in the industry to educate and entertain. Read Anthony's full bio.

Comments

  1. Erik Christiansen says

    Anthony, maths good, but a typo, if my slide rule still works:

    “42690kWh ÷ 13.8kW nominal = 30930days or 8½ years”

    “0” -> ” ” before “days?

    P.S. Pity it doesn’t like off-grid, or I could do away with the battery inverters.

    • Anthony Bennett says

      Good catch Erik,

      It is a hybrid unit and that’s what we have to explain to people. I’m only disappointed that the snap inverter range doesn’t talk to the Gen24 and they wont run in parallel. Seems a missed opportunity but that might change with firmware, if we’re thinking wishfully.

      There are some battery inverters that’re still king though… https://www.solarquotes.com.au/blog/selectronic-sp-pro/

      • I am running a 10kw Fronius Snap together with a 10kw Symo in an 3 phase system and they happily talk to each other and the BYD battery on the Symo. I didnt go with two Symo for cost and complexity reasons because two batteries and two Symo make for a complex interface with the grid.

        • Hi Paul. I have a 3-phase 10kW Snap (Symo) and I’m looking at adding a 10kW Gen24 + BYD battery. To clarify, are you saying your Gen24 can keep the second inverter online during a blackout? Or when you say “they happily talk to each other”, do you just mean that they play nice when on-grid?

          At the moment I’m trying to weigh up adding the above, or a Sungrow 3P hybrid + battery, which has some advantages like instant switching to batteries, higher charge/discharge rate from the batteries (7.7kW), lower cost, and I’ve been told it can keep my existing inverter online during a blackout (but I’m skeptical). Any thoughts appreciated.

          Cheers,
          Adam

  2. Domonic Breitkreutz says

    Definitely looks like Fronius is the way to go, but doesn’t the gen24 plus solve the issue of having a sparkie make a back up box?

    • Hi Domonic,

      I describe my system in other feedback here:
      https://www.solarquotes.com.au/blog/powerwall-alternatives-hybrid-inverters/?utm_campaign=sq_news_weekly&utm_content=230502%20weekly%20newsletter&utm_medium=email&utm_source=getresponse

      My electrician rewired my switchboard to cater the 2 inverters; I have 20 circuit breakers marked Inv1 / Inv2 / Inv1 / Inv2…etc, each inverter sharing half the house power and lighting circuits separately.

      There was no need for a separate backup box as I required all circuits to be available in backup mode.

      Only the pool heat pump is not on backup, but the filter pump is included. The electrician spent a fair time with Fronius to configure the (up to 18A / 16kW) pool heat pump to run off both inverters. I still monitor when that can and should run with available PV. At this time of the year, I set the timer for 10am to 2pm, overriding it manually for either an earlier start / later finish or off altogether during low PV production days.

      But I cannot overstate my utter disappointment in the fixed 53Hz backup mode frequency.

      I’m also disappointed to learn from Anthony’s article that the Gen24’s’ warranty is void for backup use more than 20% of the time.

      One day during the expected life of this system, Ergon will join other providers in forcing feed-in tariff times to peak hours after the sun goes down.

      The system should be able to handle being off-grid indefinitely, but clearly it doesn’t.

      Years ago I looked at a Prius and concluded hybrids try to gain the best of both worlds but include the worst of both worlds. I bought a diesel car instead.

      I’m pleased to see Finn is promoting the Australian Selectronic solution now as a proper hybrid. It’s costly but I think a better investment.
      Selectronic/Fronius insert some hardware into the inverter. But your house will run like your laptop; the operating system doesn’t care if 240V is plugged in or not, if there is plenty of battery.

      And, it runs at 50Hz all the time.

  3. That PV power point sounds like a great ‘EV charger’ for us low KM folks without having to fork out for a Zappi.

  4. Great write up! Worth updating the article that Primo Gen24 8kW and 10kW models first landing in August.

    • Rob Greenfield says

      Andrew, Do you know if there is also a delay on the Symo 10kW? My installer notified me they were having trouble locating one for our installation.

    • Hi. Do you know if gen24 symo 10 is available in Australia in the non-hybrid version or the ‘plus’ version only? Thanks.

      • Anthony Bennett says

        Hi Elaine,

        Some models of the Gen24 are only available as capable functional hybrids, they don’t offer the standard option. Sorry I don’t have a list to hand of which ones.

  5. Tim Murphy says

    How do you rationalise the 53hz frequency in backup mode – it’s not just a “coffee machine” killer – it can break poorly built switch mode power supplies in a Aldi $600 TV and a pump motor that you might rely and I know for a fact most vacuum cleaners will not survive at 53hz

    This is not a situation that should be treated as trivial as it is not

  6. Tim Murphy says

    I have already made comment about the 53hz “thing” – but I want to make another observation about the overall mood of this article.

    Designing this type of system should take a default view of actually being a proper UPS – Uninterruptable Power Supply – the view that it is acceptable to have a 90 second change over time is bizarre at best – and stating it is to ensure the grid has actually gone is ludicrous in the extreme – in essence accepting that 90 second change over is accepting a poorly designed system and accepting mediocrity.

    The health of the “plant” can be (no, should be) assured at the other end – who cares if the gid has totally gone or not – if it goes away for any period i will be in backup mode for 5 minutes regardless – this not only protects any plant deployment from multiple brown outs but also the annoyance of systems up and down and other annoying outages and change overs.

    • Erik Christiansen says

      Tim, it’s all very well to project one’s own needs onto inverter designers, but the broader considerations driving other design choices have been outlined in more than one Solarquotes blog, if memory serves. Cranking up to 53 Hz when islanding has been stated to be intended to unconditionally throttle back any other inverters on the load side. (The merit of that in any situation eludes me, as when off-grid, system capacity is only optimal if all connected array-supplied inverters can contribute. Nevertheless, that conscious design decision makes such a hybrid inverter unsuitable for off-grid use. The warranty exclusion makes that even more explicit, it seems to me.)

      Rather than regret having chosen the wrong system design for one’s use case, it seems more productive to rectify the error, and add one or more battery inverters – a great big Selectronic or a couple of Victrons. They substitute for the grid when it is absent, setting a standard 50 Hz frequency to which your currently problematic PV inverter will syncgronise.

      However, in the absence of a datanet and a compatible data protocol, there should still be frequency shifting, up to 53 Hz, when PV generation exceeds the load and battery charging requirements. To avoid delta-f in all circumstances, careful choice of fully data-compatible battery and PV inverters is essential.

      It may be worth noting that stopping frequency shift is a significant limitation for HWS power diverters such as the Jackal. When off-grid, CT sensing of grid feed-in is not available as a measure of “excess PV”, and now delta-f is out too. I can’t help wondering if the “perfect” is not at risk of becoming the enemy of the good?

      On the switchover latency, I can only wholeheartedly agree. The 90 second deliberate blackout is an unforgivable customer disservice, if it cannot be configured to milliseconds, to keep your computers on air. Add an alarm. My response is very very simple – don’t buy crap like that; buy what serves your needs.

      • Tim Murphy says

        Erik – 53hz is an abomination and many devices cannot cope with such frequency even over a short period of time – I am amazed AEMO allow them to exist in this format without being able to have the frequency configured out – as in back to 50hz – but it seems many – such as Fronius – do not allow this tuning to take place. I am luck to have a large Selectronics deployment – I am glad my own research showed the pitfalls of Fronius and I opted not to deploy them for this and several other reasons

    • Anthony Bennett says

      Hi Tim,

      I take what you’re saying but the health of the plant is something you’ll be upset about if the inverter is burnt off the wall by an unsynchronised coupling to the grid. The DNSP staff will also take exception to you backfeeding the grid if they’re trying to work on it.

      If you want a true Uninterruptible Power Supply then you need to buy one that meets the very strictly written rules. Selectronic admit they aren’t fast enough to be a true UPS (though in practice they’re seamless) Sungrow put out a specific document to explain that they are an Emergency Power Supply and should not be relied upon in the same way a UPS can be.

      See page 13 https://info-support.sungrowpower.com/application/pdf/2023/04/26/SH3.0_3.6_4.0_5.0_6.0RS_5.0_6.0RS-ADA-UEN-Ver16-202301.pdf

      I think I’ve said it before but it’s worth mentioning again, if the lights go out for 3 seconds or 20 seconds, it’s an unmissable analogue warning signal that you’re now operating on whatever battery is available. If you can’t segregate the switchboard and the refrigerative air con is grumbling away during a blackout, it’ll soon deplete your battery, so it’s worth knowing if the grid is there or not.

      • Hi Anthony,

        I understand how the +/- must be in synchronisation if 2 generators/inverters are running the same load. As a marine engineer, I must synchronise any on-coming 3-phase generator according to load. EG, Spirit of Tasmania has 3 x 1,460kW diesel generators plus 2 x 1,780kVA shaft generators.

        Instead of Master/Slave, my 2 Gen24 Primo 5.0 Plus (single phase) inverter’s each supply completely separate loads running as Master1/Master2. Apologies for the political incorrectness.

        However, they are configured to run the pool heat pump in sync; both inverters use each others PV strings to share this very high load of approx 2.8kW.

        They do this at 50Hz.

        But the grid must be connected.

        When the grid fails, there is no battery backup for the pool heater, intentionally.

        All other power sources are available in backup; I choose what I would like to run, the backup circuit not dictating to me what I can and cannot run.

        I have 9kW maximum consumption in backup, 4.5kW on each stand-alone inverter. I could exhaust my batteries from full within 90 minutes or so.

        Obviously I can and do run an electric oven or dishwasher any time of the day. The choice is mine.

        An unplanned 2-hour grid failure from 11am nearly 2 weeks ago demonstrated the near-full off-grid feature of this system: After the annoying 40 seconds delay, backup mode kicked in and most running devices picked up where they left off, including charging the 22kWh batteries.

        Except at 53 Hz.

        Dishwasher resumed its cycle. However, air comp tripped. The pool filter has its own 3-speed “frequency chopper” and began short-cycling, starting and stopping for 60/30 sec. I switched this off to prevent it overheating.

        My coffee machine sort of ran, the low-pressure pre-infuse stage not working at all, and the higher pressure infuse ran faster and produced less product. 1st-word problem but no good for the machine.

        Fronius must allow a bespoke installation that will never be run in a condition they are preventing.

        • Anthony Bennett says

          Hi Monty,

          I’ll ask about it when Fronius come to visit for technical training.

          cheers

          • Anthony, did you manage to get any information out of Fronius at your technical training?

            I’m not technical, but I can’t see why the Fronius Gen24, after the ~30 second grid isolation procedure, doesn’t reinstate the grid at 50Hz so long as:
            1. there are no other inverters/etc in the system; or
            2. if there are other inverters, make them Fronius only and controlled by the hybrid Gen24 one. With the “fail-safe” setting required in the second non-hybrid inverter. This means that if the non-hybrid inverter loses connection to the hybrid inverter that’s controlling it, it reverts to an off (fail) state therefore preventing uncontrolled generation of power*

            eg the Gen24 could be factory set to 53Hz in backup mode, with this setting changed to 50Hz by authorised installers who have ensured that the system has met on of the two above conditions.

            To just change frequency to 53Hz is a really blunt way to achieve safety, and is quite untrusting of system installers. Surely there must be a better way.

            * Similar to Selectronic Certified Fronius inverter setup shown here https://selectsupport.helpdocs.com/sp-pro/sp-pro-selectronic-certified-scert-fronius-primo-or-symo-managed-ac-coupling-installation-notes-in0049-rev-10-8-appendix-v-fronius-failsafe-configuration?preview=true

          • Anthony Bennett says

            Hi Adam,

            In all likelihood it’s possible to make a Gen24 run at 50Hz, I agree with the notion 53Hz is a blunt instrument, but you’ll have to take it up with Fronius. Bear in mind you don’t want to become “that guy” who’s wheels are so squeaky they end up driving people mad. You might possibly get extra scrutiny when it comes to subsequent warranty claims. eg the Gen24 isn’t designed to run off grid for more than 20% of the time.

            Sadly they will not allow Gen24 units to operate in parallel, nor will the older Snap series machines talk directly to the new Gen24. If they did Fronius would be in a position to wipe the floor with the competition, selling Gen24 to already happy customers.

            Happily though, if you want to update your system or expand capacity with a new flexible exports connection in SA, QLD or soon VIC, anything Fronius sold in the last 8+ years will be retro-compatible with just a firmware update.

          • Hi Anthony and Adam,

            Ergon’s requirement meant a single phase inverter can only be fitted for feed-in purposes, a maximum of 5kW.

            My pool heater, a 3kW load, is the only circuit not on Back-up. This load is shared equally between the inverters, ie “running in parallel” when the grid is connected. Only the starting current is briefly drawn from the grid, transfers a few seconds later to battery draw and soon after, if there is enough PV, is run solely from the roof.

            I treat the Gen24s as if they are not paralleled. Connecting two non-paralleled power supplies is bad juju, and will let the smoke out.

            The Gen24’s take instructions from SwitchDin’s Droplet: This from SwitchDin:
            “The multi battery self consumption controller targets the grid to always be at 0, i.e. no export, no import. It either discharges into the load or charges from the PV. Also, it distributes the set points equally between multiple batteries so they all charge/discharge at the same grade but depending on the available of power from these inverters it might slightly differ.”

            I have performed a couple of Fronius software updates up to 1.27.3-1 and am pleased to advise it retains Fronius & Switchdin functionality.

  7. Craig Iedema says

    I had I’ve of these installed yesterday. From reading this article it sounds like it is going to perform as I expect it to. Happy days.

  8. I have a gen24 and 13.8 kw byd battery
    After several blackouts this year, Ive reinstated my old small off grid system just for essential loads such as internet and computer
    The 90 sec delay from the fronius + reboot time for computer was really bad and the 53hz in backup is just wrong
    If you work from home then have a separate ups for computer and net
    My old off grid change over is less than 30ms
    And hz 50
    I should have invested a bit more and got Selectronic
    But for every day use, I’ve found the Gen24 quite and doing its job
    I would still recommend this system as it has decreased my power bill by $2000 a year
    And by the way the installers (Beyond Solar) did a very nice clean job
    I would recommend them if you’re in Sydney NSW

    • Craig Curtin says

      Greg, Just wondering if you have any UPSs online and have tried them in the blackout mode

      I have a couple of beefy APC UPS’s here (true online) and am wondering how they would handle the frequency shift to 53Hz ?

      Craig

      • Hi Craig
        The old system I have is stand alone
        No line input
        4kw MPP inverter
        800amp gel battery C10
        2000w panels
        Separate power points/GPO
        All sorted via home assistant to run daylight hours and as ups if required at night
        And if all fails I have a automatic change over switch between inverter and load
        So no 53hz to inverter
        But if needed inverter can regulate 47 -53 output hz at 50
        So to sum up – my home office is run by stand alone and the rest is Gen 24 + BYD
        If I’m not home, I can monitor both systems from home assistant-as long as NBN doesn’t crash

        Greg

  9. Rod Mattingley says

    Hi Anthony,

    Reading your review of the GEN24 makes me think that our GEH10 hybrid inverter is a much better product – rated at 10kW, four MPPT’s, 15kW max PV and no dropout on the back-up circuits in the event of a mains failure (with the latest firmware upgrade)
    How about a review of this GE inverter?

    Lomg term reliability remains to be seen.

    For installations between 6 and 10kW, with the GE inverter there is just this one item to install compared to two GEN24’s and a back up box (if going with Fronius) and no losing back-up on a mains failure!

  10. Raimundo evangelista Projetista de controle elétrico says

    Seven (7) serious mistakes in the global solar industry in the court of law; What can happen if the inverter operates with the frequency above the nominal? Magnetic field weakening. What can happen if the inverter runs below the rated frequency? Electric field weakening. 1st word problem, but not good for generating machine. Fronius solar industry 53Hz frequency wrong!! I think this is a big harmful mistake that gives justice. Customers only learn after an expensive failure. So customers, whose fault is it? The fault lies with the Pythagoreans of the alterable integration theorems. This is nonsense. If solar energy companies and solar industries don’t follow the rules, they can go to court and then to the landfill.

  11. Hi Anthony
    I was told that when a Gen24 has batteries added you can oversize your solar by 150% instead of the normal 133%. However some other Hybrid Inverters like SunGrow can oversize by 200%. This means that if you have a 3kw Gen24 you can put a max of 4.5kw of Solar. However if you had the SunGrow Hybrid you could get 6kw maximum of Solar. When running a small system this makes a huge difference. If this is true I’m thinking of throwing out my Gen24 3kw and replacing it with a SunGrow 3kw. (I can’t go any bigger than 3kw due to distance from power and voltage increase issues).

  12. Why no mention of Gen24 with AC coupled battery like a Tesla Powerwall?

    Seems to be the no brainer solution now the Snapinverter range has been discontinued.

    No 45 second wait for power changeover…just near instant on.

    Does anyone know if the Gen24 primo has and problems working alongside the Tesla Powerwall?

    TIA

  13. Thanks Anthony, great article.

    Do you know if there is a 15KW Gen 24 Symo model in the pipeline?
    I’m about to make a decision on a rooftop PV system (~15.5 KW panels), but there isn’t a 15KW Fronius three-phase model in the Gen 24 range.

    Am I losing anything significant by going with the older Symo inverter or should I wait around a bit longer?

  14. Raimundo Evangelista Projetista de controle elétrico says

    Are Fronius inverters any good? Gen24 will increase its frequency in a blackout. 53Hz frequency in backup mode is not harmful to pumps. The other gripe with the Gen24 is that when the mains fails it takes up to 90 seconds for the inverter to trip in off-grid mode. Ninety seconds seems like an excessively long time, though. Fronius recently guaranteed that the latest firmware update takes up to 20 or 30 seconds, but this is prohibited for hospitals and operating rooms.

  15. Liam John Daly says

    ” Also, your sparky will need to build their own ‘backup box’ as Fronius don’t supply a pre-built one.”

    BayWa(a Fronius distributor) builds and sells a premade back up box for Fronius)

  16. Horst Leykam says

    What’s this obsession with an extra 3Hz? Switch mode power supplies in computers and other stuff don’t care, in fact, they run happily at 60Hz which is the American standard. I can’t see any issue except life getting a bit shorter because clocks may run a bit faster.

  17. Hello, Looking to install Fronius hybrid system as well. Fronius is compatible with using Enwitec Automatic Transfer Switch for switching between grid and solar.

    What are your thoughts? Have you heard about used the Enwitec ATS?

    It is also weird how solar seems limited by transferring from grid to battery and PV supply power where switching between grid and a gas generator is super easy and happens within seconds. Do you think there is some sort of bottle neck that Fronius is still experiencing?

    Cheers!

  18. A question for Anthony Bennett….
    Existing 5kW Symo Snap inverter. Want to add a 10kW Symo GEN24Plus with a 19kWh BYD battery and 15kW more panels.

    Problem…WA rules say I need to export limit the entire 15kW of inverter capacity to 1.5kW total across all phases.

    One person at Fronius says not possible. Snap inverters don’t talk to GEN24 inverters at all apparently even for something like this.

    Looking for a second opinion…

    Thanks

    • Anthony Bennett says

      Hi Andrew,

      I’ve export limited a single phase site with 4kW Snap inverter running unfettered and 6kW Gen24 Primo (with fronius consumption meter) export limited to 1kW, which meets the 5kW total applicable here in SA at the time. To give SAPN the ability to turn this system down in an emergency under “smarter homes” rules we used a SwitchDin Droplet.

      Annoyingly the Snap & Gen24 inverters don’t talk, though they will appear on the same monitoring portal.

      I’m not sure if you can use a Droplet to solve the issue because I don’t think you can get two inverters to share a consumption meter. I’d have to ask if two consumption meters could be used, perhaps with the 5kW unit set to zero export.

      • My Symo Snap and Symo Gen 24 both talk to the Fronius Smart Meter which then works to limit my output to the grid albeit at 15kw because I have 3 phase in Qld. Is there some other talking I am missing out on?

      • Hi Anthony,

        My 2 Gen24 5.0 Primo’s each have their own Fronius Smart Meters for Production monitoring. Plus, the SwitchDin Droplet has its own Fronius Smart Meter for Gen24 #1 Consumption, AND, a forth Fronius Smart Meter for Gen24 #2 Consumption… which, confusingly, hosts each Gen24’s Supply Main Switch.

        The Droplet governs the Feed-in max, set at 5kW for Ergon, so either inverter can output zero or 5kW, or anything between.

        Can I send you a couple of photos of my setup?

        Monty

        • Anthony Bennett says

          Hi Monty,

          Go ahead and send us some images if you’d like. If you have a single line diagram that would also be fascinating I suspect.

          Cheers

  19. Matthew Wright - Pure Electric Solutions says

    The thing that sucks with Fronius inverters is there very low oversizing allowances. Should be at least 200% if not 300% oversizing allowance. They’re really stymying the renewable energy revolution with 150%. Solaredge has 200% or even slightly more if you have a battery coupled. Huawei and Sungrow offer 200% or even more.

    Come on Fronius lift your game. You’ve been our number one favourite but this low oversizing warranted figure is making it hard.

    • Anthony Bennett says

      Hi Matthew,

      I agree, perhaps we fanbois should just hang 200% on them and see if they’ll blow up?

      Civil disobedience testing so to speak.

      • Erik Christiansen says

        Mathew & Anthony,

        The one thing I’d do in that case is interpose DC breakers or HRC fusing rated at the max input current of the inverter. That limits fault current to what the inverter is rated for, and your insurance company doesn’t have an out.

        I’ve just stuffed in a total of 4 inverters, but once there are more EVs here, that has its benefits in sunny weather. (Up to 24 kW consumption.)

        P.S. Big eruptions at Grindavik yet again – perhaps due to neighbouring Greenland rising at 3 cm/year, due to 260 cubic km ice loss p.a., so all due to global heating?

  20. One downside you don’t mention is the extremely limited battery range. Just BYD and one LG model, both of which are super expensive.

    Then another $1K to software unlock the battery inverter. In my case i am looking for a small battery just to load shift away from peak. Even though i already have the hardware to do it in the GEN24, it seems the cheaper option is to install a totally separate battery inverter/charger like the Victron Multi and that opens up an almost unlimited world of battery options.

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