Hi Sebastian,
Found what was wrong with my settings after looking at the debug-info and am currently testing my electricity meter running 2 instances (docker/synology) of your component in parallel (split tariff; one for day and one for the night), which seems to be going OK so far.
Now wondering if the “max threshold” you implemented also allows for negative value as I have solar panels installed which make these counters go backwards (not seen yet as little sun these last days).
If this is / would be in place you could change the title to “Turning analog water/electricity meters into a HA sensor” 
If not in place I will put in a request for this in your github-page if OK for you.
Great work so far and thanks again,
Hans