Sorry about the confusion: I have the Emoncms system running since the beginning so i also looked at the differences with the (for me new) Influxdb.
So i’m comparing:
- the original emoncms value (based on only power (watt) input to emoncms) via serial
- export of power (watt) to influxdb/grafana and computing the usage (kWh) from that (via “webserver”)
- export of usage (kWh) to influxdb/grafana (via “webserver”)
The export with the abs etc i based on another post her on the forum, but i didn’t make the link with the operands (min and max) that are available in IoTaWatt.(i just din’t hoover over the function button… 
)
I changed my server output script and have a look at it in grafana when the data of tomorrow is available.
In the mean time i was able to setup grafana to calculate all of the values (grid/solar/import/export,…) i wanted from the power (kWh) export of Solar, grid and usage (=Solar+grid) (i think i could have left the last one out)
UPDATE: works perfect with the new script!