When the solar panels were installed in 2010, the inverter was a Aunilec Aunisol3000 which did not have an interface that allows to read out information about the electric power production. This was a bit of a disappointment for me as I had to read the production from the power meter and enter the values by hand into my database.
The Aunisol proved to be a difficult choice, at least for the electric power grid in France and it broke in summer 2011. The supplier of the Aunisol3000 unit had to replace it under guarantee, not only at my home but at many other customers as well. So the supplier decided to install a Schneider Electric SunEzy 2800 system in my home. It comes with a RS232 interface, so it was immediately clear for me that I had to connect to this device.
There is a software supplied called SunEzy Control running under Windows, but is was no option for me to install a PC that would be running 24 hours a day doing nothing else but listening to the inverter.
When I got my first Raspberry Pi, it was clear I had to connect this device to my inverter. The tasks are:
- Setup a Raspberry Pi to operate “headless” over SSH
- enable the serial port
- Prepare the required hardware, a 3.3V TTL to RS232 converter and a USB-RS232 cable
- Find out the communication protocol, connect the Raspberry Pi to the inverter and set up a generic communication
- Develop a Python script that reads parameters from the inverter frequently and stores them in a data base.
- Develop a HTML interface to display the data graphically.
- Backup the data on a network drive
- Add more functionality, like a fan