I added a little controller that collects and sends specific channel values to Meteo Control via their VCOM v2.0 API. (see https://github.com/meteocontrol/meteocontrol.github.io/tree/master/import-specification)
In the Config you can choose a pvInverter (or just a symmetric production meter), a grid meter and an ess.
You can set a measurement interval and a transmition interval, according to the Meteo Control specifications.
The Controller queries the measurements via timedata and then sends them as xml data to the meteo control server.
When you set Measurement Interval to 900 and Transmition Interval to 60, every 60 mins (1h) the controller queries timedata from the past 60 mins with a resolution of 900 secs (15 mins) puts them into the required XML body and sends it to the server.
This code has been tested with the OpenEMS simulators.
You can view my pull request here: https://github.com/OpenEMS/openems/pull/1173