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The genius of the Fronius Smart Meter lies in solving problems you never even knew you had. Here I explain the problems Solar has faced in recent years and the attempts that have been made to solve them. Then, we’ll look at the solution: the Fronius Smart meter.

Fronius Smart Meter

Solar with a smart meter

Smart Meter Screen Shot

Grey line: solar production, Blue: solar consumption, Red: grid consumption









There have been a couple of niggling issues with solar ever since the boom began. Both issues arise because simple solar relies too heavily on the effort of the homeowner to get the most out of their investment.

  • “Monitoring” meant manually reading your inverter screen and calculating efficiency. Most people didn’t bother even looking at their inverter, so faults were ignored until a big electricity bill came in..
  • People were not using the solar power when it was produced. They were selling valuable solar electricity for a measly 8 cent to an ungrateful grid. The only way to improve self-consumption was with an educated guestimate of the best time to, for example, run your pool pump or hot water, or do the washing.

There has to be a better way. Owning solar was not meant to be onerous.

The solution in Concept

The solution theoretically is simple:

  1. Remotely monitor your solar production (so that live and historical data can easily be accessed by the home owner or by an electrician). Include automated email alerts when the inverter is not performing as expected.
  2.  Monitor export power. Inform yourself of your production and consumption patterns.
  3. When your inverter is exporting power, automatically activate a switch on your pool or hot water system so that you productively use that power.

Attempted Solutions

While remote monitoring has somewhat been solved by many inverter manufacturers, it usually comes at an extra cost and often performs like a glitchy prototype.  But we are making headway; it has become less of an expensive geek’s toy and more of a standard tool for both the customer and their electrician to access.

The other aspects of “the solution” have been less successful, for example:

  • For consumption monitoring, the “Watson Meter” and “Watts Clever” seemed on paper like a great idea. However, the few consumption monitors I installed were inaccurate, glitchy and unreliable. We returned them all.
  • To increase self-consumption, the SunnyMate and ImmerSUN offered their “solar diverters”. I reviewed the SunnyMate for In summary, solar diverters do not yet financially stack up.
  • A 24-hour load shift timer was the closest we came to an economical and reliable way to limit export power. The idea is to set a timer on your pool or hot water system to run at the time of day that you would otherwise expect to be exporting power. The obvious flaw was that the system was not responsive to the weather conditions or the consumer’s irregular consumption patterns. On overcast days with less production, or on lazy weekends when daytime consumption increased, the hot water system would be pre-set to run regardless. If not designed correctly, this set-up could end up increasing your power bill compared to leaving the appliance on an off peak tariff.

The industry was clearly missing something.

The Real Solution

Enter Fronius. Their solution can be broken into three elegant sections.

  1. The Datamanager. As stock standard on the Fronius inverter, an internal Datamanager records and sends the inverter’s live production information to Fronius’ online monitoring platform; SolarWeb. Monitoring your solar on the internet is not a groundbreaking idea – many inverters have done it before. The 2015 model Fronius inverter just does it better than their nearest competitors, SMA and ABB. Fronius’s monitoring solution is so seamless; we set up all of our systems on Solar.web as part of our standard installation (about 150 systems to date).
  2. The Smart Meter. As an external add-on, Fronius have developed a the “Smart Meter”. Its primary purpose is to measure export power, but it allows so much more. Again, the device fundamentally is not new – it’s just a digital kWh meter. But it’s the integration with Solar.web that results in a user-friendly and super informative graphs and diagrams on a desktop or smartphone app. Now you not only know your solar production also but how much power is being sent back to the grid.
    Smart meter No relay

    Solar.Web phone app – datalogger plus smart meter

    Smart Meter integrated with appliace relay

    Solar.Web phone app – datalogger, plus smart meter plus appliance relay

  3. The Appliance Relay – the piece de resistance. With the information collected from the Datamanager and the smart meter, the inverter can be programmed to send a signal to turn on an appliance relay when your solar system is exporting too much power. Connect the appliance relay to your hot water system (or pool) and you have in effect turned that old hot water tank into a solar hot water system! Or think of it this way, you are turning your hot water into an intermediate energy storage device while we wait for batteries to come down in price!

With the Smart Meter, appliance relay, and a Fronius Symo Hybrid inverter, you have the best that solar can offer today, and you are ready for the very near future. Complete the above image with either the Tesla Powerwall or the Solar Battery developed by Fronius. Any further excess power can then charge your battery so you can use that power at night.

The smart meter brings the solar industry to the Golden Years. You’ve really made the grade. Enticing as a Suffragette, renegade as Ziggy. RIP Mr. Bowie, on the day I turned 40. Ashes to Ashes.

Fronius Smart Meter Spec

Mark Cavanagh

55 Comments on Fronius Smart Meter

Mark C said : administrator Report an hour ago

Hi Shaun, I may have misunderstood what you are asking, but the production on the energy balance is just what your solar system has produced over the day/month/year/total. If you had a smart meter, it would overlay your household consumption.

Shaun said : Guest Report 4 days ago

Hi Guys, I am getting on my Energy Balance screen a Production (without meter) and I can't find anywhere what that means. Can you help ?

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Ben Neville said : administrator Report a week ago

Hi Paul - Not Mark, but I may be able to help. Keep in mind the Fronius Smart Meter only reads T11 information. So, ff you had anything on off peak meters (T31 or T33) the smart meter won't be able to calculate their consumption. If you have a bill, perhaps check the T11 grid usage against the Fronius Smart Meter data, and see if it correlates.

Paul Jones said : Guest Report a week ago

Hi Mark, great article. I have had a solar system (6kW) for just over a year now with a Fronius inverter, which is great for monitoring usage. I have been doing some reconciliations with the usage reports from Solar Web compared to what I'm being billed by my electricity provider and there seems to be quite a discrepancy for the usage between the report and the actual meter readings. The meter readings (per the bill, which are actual and not estimates) for my usage is quite a bit higher than the "energy from grid" figures from the reports, some quarters it is 20% higher while others it is 42% higher. The energy to grid figures, on the other hand, almost match (out by less than 1%). Do you know why this could be the case?

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Mark C said : administrator Report 3 weeks ago

Hi Lawrence, the short answer is no, the long answer is you could probably use a second smart meter to do that. Fronius has updated their software to allow multiple smart meters. I havn't done it myself.

Lawrence said : Guest Report 4 weeks ago

Hi Mark, Thanks for the article. One question from me. If I decided to get the Fronius Symo (non hybrid) Inverter, the Smart meter, and later decided to use a third party battery solutions, example the Goodwe BP , will the smart meter still be able to give me accurate calculations?

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Mark C said : administrator Report 3 months ago

Hi Julien, it's 12 volts, but we use a din mount, single pole contactor with 12volt coil - 240-volt contact, 25 amps. The brand is Finder. neat as!

julien said : Guest Report 3 months ago

Hi Mark, will the appliance relay on a Fronuis Primo pull in a 240v contactor, or is is only designed for 24v? cheers.

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Mark C said : administrator Report 7 months ago

Hi Anoosse. It is possible that it was installed incorrectly, or it may be faulty. It would be best to contact your installer under warranty.

Annoosse said : Guest Report 7 months ago

I have a Fronius Smart meter installed wth my Fronius Primo 5.0 inverter. The smart meter recording is unreliable and doesn’t correlate with the actual meter reading. What will be the problem?

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Mark C said : administrator Report 11 months ago

Hi Stephen, most likely this would be the electrical connection between the smart meter and the data-manager card in the inverter. Possibly this has come loose? Apart from that, the smart meter may be faulty but i would say that's unlikely.

Stephen said : Guest Report 11 months ago

Hello There, For some reason my smart reader is saying its off line. Do I need to do a reset or something to get it working? The inverter is producing 5Kw but I cant see how much i'm consuming or what is going back to the grid. Can you direct me as to what steps I need to take. Thanks in advance Steve

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Mark C said : administrator Report 12 months ago

Hi Steve, if I understand you correctly, it just means that at that time you were consuming 77 percent or the solar in your home, and sending the rest to the grid!

Mark C said : administrator Report one year ago

Hi Ian. Yes, the first step is a Fronius smart meter. 95 percent of our Fronius inverters are sold with a smart meter. This will help you accurately understand your load profile and it will be able to help you size a battery in the future. Solar analytics is an even better tool than the Fronius smart meter - but you have to pay for an annual subscription.

Mark C said : administrator Report one year ago

Hi Jay, Sure we can sell it separately. If you call our office on 32683832 and ask for Ben, he will give you a price.

Jay said : Guest Report one year ago

Hello, Im wondering if you guys sell just the Fronius smart meter separately? Im a qualified electrician so the install is not an issue, im just trying to find a place that may sell them separately instead of a package. Im also wondering if you are able to disclose the price if you do sell them, thanks.

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Ian said : Guest Report one year ago

Hi Mark, In Dec '16 I had 24 panels (14 east and 10 west) and a Fronius Primo installed. Outcome has been significant reduction in import from grid, and was looking at battery (for cost reduction and partly for fallback in case of outage) and / or management systems (Choice just reviewed Carbontrack and Solar analytics) but an installer suggested the Fronius Smartmeter. We have a pool pump 1.45kw and a cleaner which I use only when cover is removed (not heated as I gave up roof space for the PV cells), 3PH reverse cycle ducted aircon (which gets a workout in cold winters and hot summers) and 400l off peak HW (4800w). I am paying 27c for import and receiving 12 cents for export until Dec 18 when it will drop to 9cents. Ave daily import since installation is 23.4kwh and export is 9kwh, I was also thinking of a heat pump for the pool to make the shoulder seasons a little more comfortable, but am not convinced on that. I realise that I cannot be energy independent on those figures, but want a better cost outcome. Do you agree a battery is not an option on these numbers? Is there any other way of backup in case of grid outage? Would the Fronius smartmeter be a worthwhile option, even if only a first step? Ian

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Mark C said : administrator Report one year ago

Hi George. Yes kind of, if you direct connect your smartphone to the inverter while at home and go into setup. But in reality no. The relays we use have an inbuilt bypass switch. If not, a separate bypass switch should be installed.

George said : Guest Report one year ago

Given you have the snart meter and a relay and the hw system set to use surplus production, is there a way to activate and deactivate the HW relay via a smart app or remotely if you want to heat the water on overcast days or night time?

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Mark C said : administrator Report one year ago

Thanks, Adam. In Qld, 6.6kW is usually enough for a 3.6kW element if you don't use too much hot water (around 5- 7 kWh a day). However, you are in Tasmania, you probably use more energy to heat (colder) water, and you would produce much less solar power. Yes, you can set the parameters to run for a minimum time, (eg, minimum run of 3 hours before 5 pm). One solution would be to replace your hot water element for a 2.4kW element ($200 or less?) and give it a go. OR... Email Scott young at Catchpower. He produces a "hot water diverter" which would be much more suited to your situation! Catchpower is a device that ramps the power to the hot-water element up or down dependant on solar export - you can trickle charge your Hot water all day long. Mark

Mark C said : administrator Report one year ago

Hi Mena, yes all do, but you need to get a 3rd party relay and, you need to know what you are doing :) Many sales companies are not technical enough to work it out.

Mena said : Guest Report one year ago

Hello Marc, thanks for the very informative article. Do all Fronius inverter models have the relay function? We've had the Fronius Primo installed recently and were advised it doesn't come with it. From reading on the internet though, it looks like it actually does?

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Adam said : Guest Report one year ago

Great article, thanks Mark. I have stumbled into this option of the Fronius and a little unsure as to its suitability. We have 6.6kw, Fronuis Primo and smart meter being installed this week! (sorry you're a little far away for us Tasmanians). Our (near new) HWS is 3.6kw and I'm worried there'd be limited power to run it. Does the inverter also have a 'run at this time' option to give a boost in off-peak timing?

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Mark C said : administrator Report one year ago

Dayana. I'm not really understanding, are you talking about a "fronius smart meter" or a "smart meter" supplied by your utility? I can't imagine a scenario either way where your bill would increase. The Fronius smart meter is bidirectional and it's the main purpose is to measure how much of your solar is used by you and how much is sent to the grid. It seems you are in Malasia, so there is probably local knowledge there that I can't help you with if you are talking about a Utility meter.

Mark C said : administrator Report one year ago

Hi Leo, The way regulations are, we cannot claim STC's if we were to install more panels on your IG 60 inverter. However, you could add up to 33% over the nominal power of the inverter, which is probably 8kW in for this inverter. You can theoretically use a relay, but in short, it would not make financial sense to do that. If you really want a larger system and a smart meter and relay, you are probably better installing a new additional system with a new Fronius inverter (and claiming the STC's or rebate), or consider replacing the system altogether. Mark

leo wilkinson said : Guest Report one year ago

We have 18 × 250 W panels on the roof brand Renne we have a Fronius IG 60HV inverter. How many more panels can I install with this inverter? Can I install a Fronius smart meter with this inverter? Can this inverter be upgraded to take more panels? Can an appliance relay be installed on this inverter to run to a heat pump hot water system? Can this inverter be used in conjunction with a generator in times of power outages? And if so, what alterations to our mains switchboard would we have to make?

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Dayana said : Guest Report one year ago

Hi! I have installed self consumption solar and used fronius inverter and smart meter. I notice that the smart meter reading is not accurate or not similar from what i monitor through May I know what is the main function of this smart meter? How does it work as a bidirectional meter? Let's say, if my connection is wrong, does this smart meter inference my grid supply which lead to higher energy and cause increase of monthly bill? My inverter is fronius symo 20.0-3-M and my solar system is 68.90kwp.

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Mark C said : administrator Report one year ago

Hi Allan, you would have done the setup incorrectly to start with. It's a bit complicated to explain here, but Fronius Tech advice should be able to help you 0383402910.

Steve M said : Guest Report one year ago

Hi Alan I have Fronius Primo 3.0, using SolarWeb and smartmeter. I have a 1.4kW heating element controlled by the Fronius' relay - energises when PV is GENERATING 1800W and switches off if falls less than 1400W. Your article suggests I can instead activate the relay when the Fronius is EXPORTING an excess. How do I do this - I assume it must take an 'exporting' signal from the smartmeter itself?? Regards

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Mark C said : administrator Report one year ago

Hi Colin, We'll get in touch with you. Sometimes they need tweaking which we can sort out.

Colin said : Guest Report one year ago

Hi Mark, MC Electrical installed our 5kw Fronius inverter late last year with a relay to heat the Hot Water system. All through summer the system worked well with the Hot Water being heated once during the middle of day. However I have noticed recently that the fallback override heating is also being turned on about 3:30 to 4:00 pm using mostly Grid power. This is happening on clear sunny days so it's not just the normal operation for cloudy days. Is there a problem somewhere or is this something to do with cooler days in winter ?

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Mark Cavanagh said : administrator Report one year ago

Hi Bruce, you can set your inverter to night-mode. On the inverter, go to the "setup menu", go to "display settings", set "night mode" to "on". Too easy!

bruce evennett said : Guest Report one year ago

Ihave a fronius 5kw with a 63a-1 smart meter. It works well but I dont see what I use at night when my inverter is asleep. Is there a work around so I can see my consumption at night? Your thoughts would be appreciated regards Bruce

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Mark C said : administrator Report 2 years ago

Hi Paul, this might be a WiFi issue? From my search, I don't think we installed your system, but if we did, call my office on 32683836 and Ryan will log onto your account and sort it out for you. If not, Fronius will help you out. 0383402910 (assuming your installer can't)

Paul Hart said : Guest Report 2 years ago

Hi just wondering about the Fronius solar web app keeps deactivating and now it doesn't work anymore I've tried to activate it and it won't work is there a solution thanks Paul

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Mark C said : administrator Report 2 years ago

Hi Alan, Yeh, tariff 33 is not recorded by the smart meter. In most cases, especially when you have a large solar system, you would put your hot water onto the T11 and control it with a relay. (I'm assuming you have a Fronius inverter) This means most of your hot water would heat with excess solar power). If you have enough excess power (shown on solar.web) look into at changing that around.

Alan Andrews said : Guest Report 2 years ago

Hi Mark I have just had a 7.25kw systrm installed with the smart meter assuming our power bills would be slashed. We noticed we still have a big usage that is not showing up on the app. It turns out that solar totally bypasses tariff 33 for hot water. Would we just need the Appliance relay fitting or do we need the hot water moving to tariff 11 to get it to work. We are still waiting for energex to swap our meter too. I wish I had read your blog sooner. Thanks Alan

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Jamie said : Guest Report 2 years ago

Just thought would let Mark know to check with. Power company not retailer first regarding floor heating or off peak circuit for water. Jemena do not support export of power if you have one of these circuits or they remove the off peak tartif and replace it with Full tariff. SA may be different but I got stung today .

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Mark C said : administrator Report 2 years ago

Hi Mark, sorry for the delay. No, the heat pump does not use the solar power during the day if it's on an off peak tariff. Yeh, especially considering your heat pump is old, you may want to put it on a relay and allow it to run when producing excess power. It will still be cheaper, especially if you are on t33 (about 20 cents). When the time comes to replace it, replace it with a simple durable tank. One thing you should do before we install is to turn your heat pump off for 24 hours or so, and check if you still have enough hot water. This would simulate a rainy day with no excess Solar PV. (remember if you get a week of no sunshine you can always bypass the relay) Mark Cavanagh

Mark Blayney said : Guest Report 2 years ago

hey Mark, your guys are putting a 6.6kW system in for me in May. I am getting the Fronius 5 with smart meter but opted not to pay the extra for the Hot water relay as my Heat Pump hot water is on the Low Tariff. Does the HW still use the solar during the day even if is on Low Tariff ? And I am wondering now should I still get the HW Relay at time of install anyway ? After reading about unreliability of heat pumps (mine was replaced about 7 years ago) it has got me wondering should I just have it there anyway and get a different HW system next time. Your thoughts on this please ?

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Mark C said : administrator Report 2 years ago

Hi, Bruce, for sure. Harnessing excess PV would be the most reliable and cost effective way of heating water. In fact, that's what I'm doing to the house I am moving to soon!

Bruce said : Guest Report 2 years ago

Hi Mark Good article on the frontius with load switch. I have a gas tank storage hot water nearly at end of life. Would i be best to replace it with conventional electric hot water storage and feed it from a frontius PV with load switch Regards Bruce

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Peter Elepfandt said : Guest Report 2 years ago

Hi Mark, great article! How far away can you have a relay from the inverter? I've got the panels and inverter on the shed but obviously would need to switch the pool-pump and water heater at the main switch board at the house. The Ergon Homesmart system they are trialing seems to offer a system that would have similar functionality and a bit more. Unfortunately I missed out on the rollout... Regards Peter

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Plu42jiKoyh said : administrator Report 2 years ago

No, in short you can't monitor the two systems with a Fronius smart meter. It throws the figures out - because the calculation relies on knowing the production of both inverters. You'd probably need to use solar analytics or something like that to monitor the entire system. The smart meter can only be used if you have multiple Fronius inverters. Mark

Mark turner said : Guest Report 2 years ago

Hi I am about to have a second system installed ie: 2 separate strings with different outputs and 2 separate inverters 1 being a fronius which is the newer of the 2 and the other an Aurora. My question is does the energy consumed and made all pass through the fronius smart meter or will it only monitor the new system? Thanks

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Adam said : Guest Report 2 years ago

If the hot water system is set up with the Fronius inverter, smart meter an relay, is there way to fall back to off-peak power during winter rainy days when there is little sun?

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Plu42jiKoyh said : administrator Report 3 years ago

Hi Peter, The smart meter gives the information to the inverter which then operates a 12-volt signal. We use that 12-volt signal to pull in an external 16a relay for a hot water or pool circuit. Different parameters can be set in the inverter for when the signal should activate, minimum and maximum run time etc. I guess there are a number of ways you could use it.

Peter said : Guest Report 3 years ago

So its an output from the Smartmeter when there's an excess exported to grid? This could then be used into a small PLC to control multiple outputs I gather?

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Plu42jiKoyh said : administrator Report 3 years ago

Hi Tom, Yes the Fronius can control a relay that can really switch anything. Sounds interesting, let me know how you go with your superchiller!

Tom said : Guest Report 3 years ago

Here is a follow up on Ruth's question. I don't need to heat my hot water tank during the day, my solar thermal system already super heats my hot water. Can the Appliance Relay be connected to a fluid cooling unit when I have excess solar energy being produced? I envision a tank that could store super chilled antifreeze combined with a heat exchanger connected to my AC unit to be used to aid my AC during the evening/night. This could serve as another (non battery) energy storage device for my home rather than exporting excess solar generated energy at a low tariff to the grid.

Plu42jiKoyh said : administrator Report 3 years ago

Hi Ruth, Not really. What we often do is set one of the appliances to run on relay 1 when there is more than (X) amount of power is being produced. The second would go on the relay 2 and the appliance would only work if the solar has excess power that would otherwise be sent to the grid. If you are lucky enough to have an EV, then it gets difficult to do the third appliance, but it could work with two timers and one relay. It really depends on the load of each appliance and the order of priority. Mark

Ruth said : Guest Report 3 years ago

Thank you for your article. I'm just wondering if you can set priority relays depending on the amount of excess power? I'm thinking of heat pump hot water, then storage heaters then pool pump when there is spare and one day an EV in the mix also! Many thanks Ruth

Plu42jiKoyh said : administrator Report 3 years ago

Hi Peter, no (if i understand your question). The Fronius smart meter can allow the inverter to acuralty controll a relay (not a timer). But the relay is not built into the Fronius smart meter or the inverter. We would have to install that seperalty. Mark

Peter Ryan said : Guest Report 3 years ago

Hi Mark would it be right to assume that if I had the smart meter fitted I could drop off having a timer relay fitted for the hot water .

Alan said : Guest Report 3 years ago

Will it work on an off grid system?

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