2014/10/16

Electricity Metering with Flukso

For over 2 years now, I’m monitoring my photovoltaic panels with the sma-bluetooth application running on a Tonido2 plug-computer (http://michael-peeters.blogspot.be/2012/04/sb-inverter-bluetooth-connection-on.html). The data is sent every 10 minutes to the excellent pvoutput.org site where it can be viewed directly from a browser or through an Android app. This setup is running surprinsingly stable for more than 2 years now.
Flukso device wired up with 4 sensors (water, gas,
 electricity consumption and production)
I was looking for a cost-efficient way to also monitor my electricity consumption. After some research I discovered the flukso device (https://www.flukso.net/about). It is a cheap device from a company in Leuven (Belgium) that allows to monitor electricity through current clamps and / or by counting signals on pulse ports. The flukso device itself is opensource and based on openwrt (https://openwrt.org/). Besides energy consumption, it’s also possible to measure (solar) energy production. In addition, it has support for measuring water and gas consumption. The Flukso also comes with a free webservice to monitor your energy usage at all times.
The Flukso device is well-thought but requires some DIY skills, research and careful preparation as not all setups are compatible. Here are some findings / considerations when using the device:
  • I bought the FLM02B version as it has support for 4 pulse ports. This allows me to monitor 4 different things: electricity production (solar panels), electricity consumption (3 phases), water and gas. If you don’t need all the extra meterings possibilities, the FLM02A might be enough for you.
  • As an alternative to measuring your power consumption with power clamps, you
    Flukso device connected to power consumption
    and production meters
    might consider buying a cheap DIN power meter with an S0 port. Before buying a DIN consumption meter check out if the pulse/kWh rate is supported by Flukso (1000 pulses/kWh works best). In my case, the power meter turned out to be cheaper than buying the 3 powerclamps — although I got the insight a bit late :-). You can also ask for the lastest alpha-version of the firmware to overcome some issues with other pulse/kWh rates (see https://www.flukso.net/content/3-phase-not-measuring-correctly?page=1).
  • Checkout if your solar power meter has a S0 port. I only had to wire up the “Carlo Gavazzi 2 kWh” S0 port to my flukso. (http://www.carlogavazzisales.com/pdfs/EM10-DIN_Datasheet.pdf)
  • Check out if your installation can correctly separate consumption from generation. Although this seems obvious, my solar power was injected “somewhere” in the breaker panel, making it impossible to monitor consumption only. After some rewiring of the breaker board by an electrician and installing the electricity meter, everything went fine (see: https://www.flukso.net/content/seperating-household-consumption-and-generated-power).
  • I’m using an ethernet cable to transfer the pulse-signals from my water and gas meters. Although I had some hesitations, this does work fine over a distance of 10-15m. (see https://www.flukso.net/content/maximum-pulse-wire-length-and-wire-used)
  • I had some trouble with the gas sensor. By bending the cable and pushing the sensor upwards, everything worked OK https://www.flukso.net/content/elster-bk-g4m-positioning-sensor).
  • The ‘shop’ pages contain the right constant values for the water and gas sensors; I’m having the exact same models as depicted, so this was easy: https://www.flukso.net/content/water-probeand https://www.flukso.net/content/gas-probe
  • by default, the locale web-console only accepts connections over the ethernet port,
    not over Wifi. This is a security feature, but it can be changed if you wish. See https://www.flukso.net/content/access-flm-wireless-interface to enable it: ssh root@ip.to.flukso (password: root)
    uci set firewall.@zone[1].input=ACCEPT
    uci commit
    /etc/init.d/firewall reload
    
    You can also change the password with passwd
  • with ssh, you can access the syslog with logread and logread -f
    http://www.xinotes.net/notes/note/1510/
  • I had a few issues with unreliable connections. After some trial and error, it turned out to be simply a matter of correctly connecting all cables :).
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