Pimatic plugin to gather power consumption from Efergy E2 (and other clone devices including Chacon EcoWatt) using a RTL-SDR compatible dongle. This plugin use the rtl_433 executable (https://github.com/merbanan/rtl_433)
Compiling rtl_433 requires rtl-sdr to be installed.
Depending on your system, you may also need to install the following libraries:
sudo apt-get install libtool libusb-1.0.0-dev librtlsdr-dev rtl-sdr
See rtl_433 readme for more details.
Thanks to merbanan and the rtl_433 community for their support and to maintain that very nice tool.