Connecting an E.ON EnergyFit Monitor to Google PowerMeter

This content is 14 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

The energy company that I buy my electricity and gas from (E.ON) is currently running an “EnergyFit” promotion where they will send you an energy monitor for free. A free gadget sounded like a good idea (I have a monitor but it’s the plugin type – this monitors the whole house) so I applied for one to help me reduce our family’s spiraling energy costs (and, ahem, to help us reduce our environmental footprint).

The EnergyFit package appeared on my doorstep sometime over the weekend and setup was remarkably easy – there’s a transmission unit that loops around the main electricity supply cable (without any need for an electrician) and a DC-powered monitor that connects to this using a wireless technology called C2, which works on the 433MHz spectrum (not the 2.4GHz that DECT phones, some Wi-Fi networks, baby monitors, etc. use).  Within a few minutes of following E.ON’s instructions, I had the monitor set up and recording our electricity usage.

The monitor is supplied with E.ON’s software to help track electricity usage over time and it seems to work well – as long as you download the data from the monitor (using the supplied USB cable) every 30 days (that’s the limit of the monitor’s internal memory).

I wondered if I could get this working with Google PowerMeter too (Microsoft Hohm is not currently available in the UK) and, sure enough, I did.  This is what I had to do:

  1. Head over to the Google PowerMeter website.
  2. Click the link to Get Google PowerMeter.
  3. At this point you can either sign up with a utility company, or select a device.  The E.ON-supplied device that I have is actually from a company called Current Cost so I selected them from the device list and clicked through to their website.
  4. Once on the Current Cost website, click the button to check that your device will work with Google PowerMeter.
  5. The E.ON EnergyFit monitor is an Envi device – click the Activate button.
  6. Complete the registration form in order to download the software required to connect the monitor to Google.
  7. Install the software, with includes a registration process with Google for an authorisation key that is used for device connection.
  8. After 10 minutes of data upload, you should start to see your energy usage appear on the Google PowerMeter website.

Of course, these instructions work today but either the Google or Current Cost websites are subject to change – I can’t help out if they do but you should find the information you need here.

There are some gotchas to be aware of:

  • The monitor doesn’t keep time very well (mine has drifted about 3 minutes a day!).
  • Configuring the monitor (and downloading data to the E.ON software) requires some arcane keypress combinations.
  • According to the release notes supplied with the Current Cost software, it only caches data for 2 hours so, if your PC is switched off (perhaps to save energy!), Google fills in the gaps (whereas the E.ON Energy Fit software can download up to 30 days of information stored in the monitor).
  • You can’t run both the E.ON EnergyFit and the Current Cost Google PowerMeter applications at the same time – only one can be connected to the monitor.

If your energy company doesn’t supply power monitors, then there are a variety of options for purchase on the Google PowerMeter website.

7 thoughts on “Connecting an E.ON EnergyFit Monitor to Google PowerMeter

  1. Mark, I notice you posted problems with the install of the E.ON software and were searching for a fix. I too have error messages (I’m using Windows 7). Did you ever find a fix?

  2. Hi Mark, I don’t seem to recall having too many problems with the Energy Fit software: it installed OK on a virtual machine I have that’s running Windows 7 (32-bit). Suspect it may not have liked the main (64-bit) installation that I use for work. This post was just because I realised that E.ON’s monitor will also work with the Google PowerMeter site… with a bit of effort!

  3. Hey there, Thanks for the post, got mine up and running with Google PowerMeter.

    If you get a second could you post the instructions on how you got the E.on’s monitor software working with Google. Also does it have the same issue with the buffer of 2 hours or will it take the 30 days data?

    I came across something called “the Bridge” which uploads data automatically however its yet another thing which needs to be plugged in!

    Starting to think its all a con to use more power. =)

    Thanks again

  4. @Mike – it looks as though I may have confused people here. I didn’t get E.ON’s software working with Google: I got E.ON’s monitor working with both E.ON’s software or Google PowerMeter (as described here), but the monitor can only be connected to one applcation at a time, and Google’s needs the PC to be “always on”.

    Because Google PowerMeter needs an always-on PC, I’ve fallen back to using E.ON’s software, and downloading data from the monitor every few weeks (making sure I don’t hit the 30 day limit).

  5. Hey there, thanks for the update, the “current cost” software (v1.0.2) also has a history option which I have been using to upload to Google PowerMeter which seems to be working well with accurate data, this does not seem to have the two hour buffer limit as the live data upload has. The big downside is it is a faff to remember to do it so….

    I have also just bought (at huge cost, in my opinion) a “bridge” which should automate the whole process as I know I will forget to do the upload and I like the thought of live data.

    I got it from Amazon but it has a 40 day lead time!!!!!!

  6. Hi Mike – thanks for telling me about the history option in the CurrentCost software – I must have missed that. The bridge sounds interesting… do you have a link?

  7. Hi there,

    I have just uploaded my history for the past 24 hours it took two attempts but the second time it worked, (first time it only uploaded an hours worth of data)

    a link to the bridge is

    I like the idea that it is live data, but again it uses power! I thought the whole point of this was not to use power.

    having said that I have found some interesting data about our hot water which should save us a nice lump of money…

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