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Fronius Smart Meter

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.

Solar with a 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 integrated with appliace relay
Solar.Web phone app – datalogger, plus smart meter plus appliance relay
  • 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.

    Dowload The Fronius Smart Meter Spec

    2023 Video Explainer with Fronius

    Fronius Smart Meter

    Mark chats with Dan from Fronius Australia about why a Fronius smart meter may be worth adding to your solar installation. From battery simulation to exposing the sins of your power consumption to export limiting, they explore the benefits as well as pitfalls of not having one.

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    Mark Cavanagh

    Mark is the Owner and Manager of MC Solar & Electrical. He’s an Electrician, accredited solar installer/designer and an electrical contractor.

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