Measure energy usages with gpio

[Amsterdam020]

I would like to measure the energy usage of a couple of appliances with gpio, rather then WiFi, zwave or 433mhz.

Online I found this how to
https://www.hackster.io/ControlEverythi ... -pi-190a2a
For this products
https://shop.controleverything.com/coll ... monitoring

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2-CHANNEL ON-BOARD AC CURRENT MONITOR FOR I2C
Solid Core Current Sensors
High Accuracy
0x2A I2C Start Address
Regular price$53.95
AMPERAGE - ACCURACY

Current monitoring of your AC power loads is now possible using cross-platform I2C communications, making current monitoring possible for your Raspberry Pi, BeagleBone, Arduino, or any other computing platform that supports I2C.

Monitor current and keep track of your power consumption using your favorite computing platform. This controller has two monitoring channels, precision tuned to monitor the current flow through the on-board current sensor with a 3% or 5% maximum error rate (See Technobabble below).

To use this device, simply run an AC power wire, up to 10 AWG in size, through the center of the sensors. The on-board custom designed CPU will do the rest using I2C communications.

This controller includes an I2C expansion port, allowing expansion for more current monitoring inputs or other types of I2C sensors and devices. Four on-board address jumpers allow expansion of up to 16 current monitoring devices through the I2C expansion port. Mix and match current monitoring controllers of any size to meet your specific application requirements.

Software developers can take advantage of our ControlEverythingCom GitHub repository for current monitoring and programming samples.

This device only requires a 12VDC power supply for operation, which may be plugged into the controller using a 2.1mm center positive barrel connector or on-board terminal block for direct wired power supplies.

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I believe this can be price wise an attractive solution.
Has somebody experience with this product from "control everything"?