It is now possible to capture those 10s to 20s power consumption samples or Efergy E2 Transmission raw data through use of a RTL-SDR USB dongle connected to a Raspberry Pi. The Rspi runs on a fedora Linux OS with the C code decoding software installed.
Here are a couple of sample screenshots where the app reads data from the dongle using rtl_fm and a C program that decodes the baseband data and displays the computed values in CSV format;
Output data is printed in CSV format and can be captured and saved for excel use such as this one ;
The source code can be downloaded here,
A more detailed writeup of the software decoding can be viewed at Gough's Tech Zone