Thanks a lot for your quick responce.
I will start reading first...

Hello,
I spend some time to show the output of my two GoodWe Inversters in Domoticz on a Pi using the GoodWe solar inverter via SEMS API. Once I got the hang of it this base works fine. Nice!

Since I own two inverters I would like to sum up the totals: current power (Watt) and the total energy ...