Ev charging and Solar energy


I am considering investing in open energy monitoring. I was just wondering which products i would need if i wanted to measure my general home energy consumption, EV charger consumption and PV energy generation separately. Also would i be able to extract the raw data to graph each input repeatedly on a half hourly bases ?

Well, the base emonpi will not have enough CT inputs (you need at least three) so you will have to consider other options. My system is quite old and so consists of an emonpi with only the optical pulse input used but it acts as a base for an emonTX 3 with 3x CTs (grid, solar, evse), an optical pulse input and the AC reference PSE plus an emonTH for various environmental monitoring and finally an MQTT relay for turning the EVSE on/off via a contactor in the consumer unit.

Nowadays there are more options and I will leave it to other who have used them to suggest if the iotawatt and/or emonTXv3 with wifi are good starting points instead of my set-up.

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hi peter,

thanks for that ill have a look into it

I would recommend an emonBase (= Raspberry Pi plus RFM radio, runs emonCMS) to receive data from an emonTx V3.4.

The emonTx has one voltage and 4 current inputs (all the details on the ‘Shop’ website, linked at the top of this page) so leaves you with one spare input.
If you are likely to want a further 2 current inputs, then the emonPi would be preferable in place of the emonBase. (emonPi is a RPi plus a 2-channel emonTx in one box, emonBase doesn’t come in a box, and doesn’t have current, voltage or temperature inputs like the emonPi.)

I don’t know about, so can’t recommend, Iotawatt. This is not the best place to ask about that, I suggest The IoTaWatt forum is the place to ask a question that is specifically about the operation and use of IoTaWatt. That is managed by Bob Lemaire, its creator, and he and the other users there are more likely to have the specific knowledge to help you.