Flukso – Wifi Household Power Logging

The Fluksometer is a Wifi device that measures your household power using a sensor that clips over the mains cable in your fuse box. The Fluksometer then associates with your Wifi network and automatically logs power data to the Flukso web site. Your data can then be viewed via your account on the Flukso web site:

When I see graphs like this I am shamed by my profligate energy use so I go stomping around the house yelling at children and switching off lights!

The Web is pretty cool for connecting people with related interests. I met Bart from the Flukso project through a post to the Village Telco Google Group. Bart was working on similar technology to the Mesh Potato – an Atheros based Wifi router coupled with a micro-controller to help interface analog signals. However instead of telephony, his device logs household power consumption data. Just like the Mesh Potato, the Flukso project is also open hardware. Very cool. I am really interested in minimising my household energy consumption, so I bought one of the Beta Flukso’s as soon as they were available.

The kit comes in a very nice box with very simple, easy to read instructions printed on the outside:

Here is the kit of parts inside the box:

The Wifi router is tiny – just 6 by 9 cm. The OpenWRT based GUI is extremely simple to use, just enter a few details of your Wifi network and that’s it. You do need a power point for the Flukso near the fuse box. In Australia many of our fuse boxes are outside so this can be tricky. As a start I extended the DC cable a few meters into the nearest room of the house. I’ll get a power point installed inside the fuse box soon.

Hacking my Fuse Box

Don’t try this at home. Get an electrician instead.

I have a grid connect Solar PV system which complicated my installation a little, as my house exports electricity during the day. The Flukso sensor can’t sense direction so initially I could see my day-time electricity “use” going up as the sun rose overhead and PV system exported electricity.

What I really want to know is how much power the house is consuming. This is actually obscured by the PV system. For example if the PV system is generating 1000W, and the house is using 1200W, I will be importing 200W from the grid. My house electricity meter and the Flusko will read 200W as they are measuring net power. I would get the same reading if the house was using 200W at night with no solar power being generated. In both cases all I get is a net reading from my power meter of 200W. So the problem is to separate out Solar PV power from the household power consumption by clamping the Flukso sensor over the right wire in the fuse box.

In my case some editing of the fuse box wiring was in order. After discussing the problem with Bart and Dickson (an electrician friend and fellow EVer) I worked out what I needed to do. So one Sunday morning while the house was quiet I armed myself with a pair of rubber gloves and a screwdriver. After shutting down the power via the main breaker, and the solar power via the solar breaker, I took a cautious peek inside my fuse box:

The solar breaker is on the far right. It feeds current into my power system via the long red wire that leads to the main breaker on the far left. Here is a close up of the main breaker:

The mains from the grid enters at the bottom, the top are the various connections to my house. One of these wires is the solar power, the other two lead off to various household circuits via other breakers. The top of the main breaker was being used as a junction, making it tricky to separate solar from household power.

What I wanted for the Flukso sensor was a single wire that had all of the household power flowing through it. This wire should be separate from current flowing from the solar system. So I went to work with the screwdriver and moved the junction points to some of the other breakers. This left me with just two wires connected to the house side of the main breaker, the solar and “everything else”

Note the Flukso current sensor clipped over the “everything else” wire. Dickson said to make sure that the extra wires weren’t wired to the main breaker for a reason (for example high current load). However these circuits lead to minor loads so I figured I was OK. With the minor rewiring job I ended up shortening the entire path anyway.

Next steps

For the record I currently use about 22 kWh a day (large house with a pool, 5 people, 4 TVs including one flat screen, 4 computers in daily use). I work from home so the house is in use during the day.

An average of 6kWh is for the EV – this I have no problem with as my Solar PV generates an average of 8kWh/day so it’s fossil-fuel free driving. Even when we charge at night it’s electricity made right here in South Australia (approaching 20% wind power in South Australia, with much of the balance natural gas power stations) rather than running my car on nasty, rapidly depleting foreign oil (Australia is way past peak oil production, we import 70% of our oil).

But the 16kWh balance annoys me. I am in the process of tracking that down by performing another power audit, this time with a more accurate power meter that can handle inductive loads. I am sure it’s the kids, but another audit will no doubt point to my office like last time. My goal is 10 kWh/day, excluding the EV.

Bart also suggests this approach: “When the kids are asleep, pull out all electrical appliances, especially heavy users like your fridge. Then look at the reading on the ‘hour’ chart. Switch off the fuses one by one (except the one the Fluksometer is drawing its power from!), while looking at the hour chart in between those switch-offs. You’ll have to wait a couple of minutes to see the result. When you notice a big drop in consumption, you’ll at least know which circuit the phantom load is on.”

Managing Household Energy Consumption

A similar product already available here in Australia is the Centameter. This has a sensor that talks to a wireless display via a short range wireless link (not Wifi). The big difference with the Fluksometer is that it is built around Web technology. This means you can access the data anywhere (for example while out of town or at work), and do lots of clever things like examine your homes historical power usage over time and seasons and compare with other peoples usage patterns. Here is an example of my power consumption compared to Barts:

Bart puts me to shame!

One other difference is that the Centameter sensor doesn’t require AC power near the fuse box (although it does need batteries) or a Wifi Internet connection. The Fluskometer (85 Euros) costs roughly the same as a Centameter (about AUD$200).

BTW these devices usually pay for themselves very quickly. To recover the $200 in 1 year at my current electricity rate (18 cents/kWh) works out to 3kWh/day, or just a 125W load running 24 hours/day. However for me it’s more than the $ – it’s about needless waste and the folly of burning irreplaceable fossil fuels.

Both devices share a very important principle – if you can measure your power you can manage it. Reducing power consumption (Negawatts) is by far the most powerful alternative energy technology we have today. A good example is our household. We have dropped our electricity consumption by 50% and are now shooting for 70% and we use maybe 10% of the petrol we used a few years ago.

Buying a Flukso

If you live in Australia you can buy a Fluskometer from the Store. If you live in another country please contact the Flusko Project for other purchasing options.


[1] Flukso Web Site
[2] EV Battery tester – another use for a Wifi router connected to a micro-controller.
[3] Halving my Gas and Electricity Bills

34 thoughts on “Flukso – Wifi Household Power Logging”

  1. I recently bought the Fluksometer too. It’s daunting to see your actual real time electricity consumption. It’s too soon for me to see strong patterns, but it’s already hightning my awareness to the fact that there is inefficiency in our power usage. Indeed not using the energy is the cleanest energy there is.

  2. I was looking for similar hardware and came up with this:


    No WiFi, but it does have a wireless (Zigbee) remote display, and can connect to an ethernet cable…

    €85 for the Flukso, plus we have “split-phase” wiring here in the US, so €18 for another coil… the TED device is somewhat more expensive ($240 with external display, $200 without) but it is interesting that it works with Google Power Meter (http://googleblog.blogspot.com/2009/10/google-powermeters-first-device-partner.html)

    If I could save 10% on my annual electric bill, I think that this thing would pay for itself in the first year!

    By the way, I did enjoy looking at your electric panel. Very different than how things are done here in the US, where wires are a lot fatter because the amperage is higher, red and black are both hot, etc.


  3. Can you install two current clamps, and have it treat them independently? This would allow you to put one clamp on the solar (feed-in) and one everything else (buy).

    Can you configure it to also send the data to a local server?

  4. Russell – there is only one sensor input. There is no specific way to send the data to a local source but I heard of one guy who is capturing the packets being sent to the server. It’s an open project so I imagine both of these features will emerge in time.

  5. Thanks David. The three phase version has three sensors, and it would be normal to sum the currents in each phase. I think it would be interesting to use the 3 phase kit with one sensor on the solar feed-in and one on the household usage wires. These could be treated as separate measurements, but displayed on the same graph (one line for generation and one for usage).
    Is there a forum for asking the developers about questions like this?

  6. The Flusko sounds like a bit of a break through.
    If the wireless link to my ADSL/router is simple and secure, and it can feed my data to me for a bit more crunching and graphing (which is what I do) the I’ll have one thanks!
    Inaccuracy is an issue that Centameter, Efergy etc suffer from so I hope this unit is much better.

  7. Ive just bought one of these flukso’s. Ive got a powerpoint in my meter box & ive run LAN cable to the meter already, all ive got to do is clip it in. My situation is very similar, ive got the feed in solar wire coming into the main breaker same as you & also they are using the top of the main breaker as a junction.

    I was thinking of clamping the sensor over a bunch of cables, excluding the solar feed. Does anyone know if thats possible? Otherwise it might be easier to move the junction to a different point. Where did you move your bunch of wires? to the bottom of the first breaker?

    Depending on how well the flukso works, I might buy another one & use that just to monitor solar output.

  8. Hello Wozza,

    You don’t actually need a LAN cable to the Flukso, I connect using wireless. Yes I think you can clamp the sensor around several cables carrying the AC. I moved the wires to other points on the same electrical “node”, which happened to be the input of some adjacent breakers a few inches away.

    Please re-read the note above from my electrician friend Dickson – you need to make sure those wires aren’t connected to the main breaker for a reason, like very high current loads.

    – David

  9. Hi David
    I hate wireless, for me its always been a poor alternative to wired. It was very easy to run a LAN cable to the meter box anyways.

    Thanks for the tip, thats EXACTLY how I was envisioning doing it. I will move one or two low current wires to the input of the next breaker until I can clamp over the remaining wires.

    We’ve just had our evap system put in, my next project will be a temp / humidty sensor in every room, outside & the roof cavity to monitor temperatures everywhere in the house. Would be great to have it web connected like the flukso, aim planning a whole house monitoring system.

    Thanks for the help.

  10. Ok maybe check with Bart on the Flukso forum to ensure that wired LAN works as automatically as Wifi.

    Also on the Flusko forum Bart just mentioned that the latest Fluksos have multiple sensor inputs “pre-wired” in software. So it should be possible to add other sensors of you can work out how to process the data.

    Monitoring the roof space temp would be great, I would like to work out where any insulation “hot spots are”, e.g. on a hot day where is the heat getting into the house?

    One other nice thing about evap air con is you can fix it yourself. The motor in my 20 year old evap system just seized during a recent heat wave. But I managed to pull it out myself, and the local electric motor guy put a new bearing in it for $120 and I was back in business. Not bad seeing I was quoted $5,000 for a new air con. No way I could have serviced a heat-pump type air con.



  11. I got my flukso going without having to re-arrange any wires. I managed to get the clamp around every single wire except the solar feed, it was a fairly snug fit, not a mm to spare. I want to get another flukso & clamp it on my solar feed, so my power consumption & generation graphs are superimposed on each other. So as I expand my system with maybe a small wind turbine or more solar, each renewable energy feed will be logged by the 2nd flukso.

  12. Hi David,

    The Cent-a-meter has been an expensive flop for me; replacing batteries, poor reception, no logging, etc. Thanks for your article in Renew and blog post. I will get a Fluksometer. Now I need something very similar that broadcasts my PV array’s output to a web site. The Fronius Datalogger Web is what I am looking for but at $2,285.00 it is just a ridiculous price. You would know what parts are in it which makes the cost that much more obscene. Got any suggestions for an alternative?

    Any help appreciated.



  13. Hi Karl,

    The latest Fluksometers have two channels, I am using one to plot my household electricity consumption and the PV array’s output. Here is today’s plot:

    They cost just a little more (AUD$25 extra) for the extra sensor. I’ll have stock in about two weeks.

    – David

  14. Excellent, thanks David. I’ll be in touch in about two weeks. Or if you could let me know when you’ve got stock, that would be great.

    Thanks again. I’m so glad I got in touch with you.

    Cheers, Karl

  15. Hi David.
    Problem with being a sparky, always looking to clean up.
    3 phase RCD’s take up so much room in 1 phase installs like yours unless your contemplating 3 phase. Busbar cleans it up to and increases intergrity of connections to breakers.
    Anyway less of that sorry.
    I’m hoping in the software that it will be possible to allow for the leading power factor of the solar output as this seems to play some havoc with readings of standard monitors i’m led to believe, do you reckon it’s possible

    1. Hi Jeff,

      Thanks for the clean up ideas! I thought solar inverters adjusted themselves to be in phase with the mains but I am not sure. If you have a feature request try posting to the Flukso forum, that’s where all the development action is.

      1. Controlling phase difference is how solar inverters (or any generator) export power. The inverter will lead the utility supply phase by several degrees (depends on their coupling impedance) which in turn results in voltage difference between the two sine waves and consequently power is exported.

        My inverter will lead or lag by up to 25 degrees to allow it to import or export power. When the sun isn’t shining, the inverter lags to import power and maintain battery charge. Interestingly, reactive power and inrush current for starting motors etc. is supplied by the inverter, so the grid sees a smoothed load and a PF of one.

        1. You can also export power by making the inverter act as a current source, keeping unity power factor. This is something that isn’t easy with a rotating generator.

          If you also vary the phase, then you can correct for household appliances with non-unity power factor.

  16. Hi David,.

    Any idea when you will have flukso in stock again.
    Also would like to know if there are any connections methods available for it that could use a 2 channel 3 wire DIN 43864. For a direct metering application.
    Will ask at the forum unless you have come across this already?

    Regards Jeff Peate.

    P.S. Top Web Site mate love it.

    1. Hi Jeff, Bart from the Flukso project is getting very close to releasing a new Fluksometer. You can email Bart direct or post to the Flukso forum for more information.



  17. Ive had my Flukso2 for a few months now (thanks David) A great piece of equipment for a fair price :)
    Very happy with it. I did replace the current loop sensor on my solar feed line with a pulse output kwh meter ($38)
    as I was getting a phantom 109watts at night 0 now.
    The new graphs at https://www.flukso.net/chart is a big improvement over the original Dash and is to be improved even more. The support for the Flukso keeps growing with an Android phone or tablet app https://www.flukso.net/content/android-flukso-viz-alpha-release?page=3#comment-915 and PVoutput.org now directly linking the the Flukso api.


  18. Flukso is now supported on PVOutput.org
    Set up is a straightforward entry of numbers.
    Temp comes from weather underground the same way.
    This is mine: http://pvoutput.org/intraday.jsp?id=1335&sid=4380&t=0&gs=3&s=1

    You can get a better usage/analysis of your data transmitted from the Flukso there. Mine shows Solar power, consumed power, daily temp, $$ saved from solar credits etc etc.
    I have installed 2x din rail kw/h meters with a s/o output for both solar and consumption and removed my current clamps for more accuracy. These are supported by the Fluko module.

    bazzle01 (at) hotmail.com

  19. Hi David,

    this page inspired me a while back and I went ahead and bought a flukso. I’m really pleased with it, and logging my solar and demand data. I also have a script set up to download all 1-minute resolution data once a day so that I can save it. Thanks very much for posting all this online.

    I’m now looking to measure not just my demand but also my power quality. In other words, voltage, frequency, power factor, etc. Do you know of any web-enabled devices (like the flukso) that do this?



  20. Hi;

    Is it possible to store the Log files on a private server? Like a personal NAS(Network Attached storage) ?

    Can i get the log data out of it? to import it in excel? to make own charts?

  21. Hi All,
    Is the AC voltage monitored by this device, i can only find references to current? if not then how can the power be derived accurately? P = Vrms X Irms

    Looks like a nice device :-)


  22. With respect to Bazzle’s question, I am honored that (parts of) my visualization/content are reused to show how well the Flukso is (can be made) capable to also show its measurements; yet it would be just fair to provide a proper link, especially when there is a royalty free license involved. Thanks.

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