Daily cumulated Value´s ,from a precalculated value


I want to refresh the dashboard of my PV and have some questions.
I try my best to explain it in english but i am german. So please be patient with me when i use some wrong words or phrases.

First: I have a raspi4B with iobroker and some instances running (homematic ip, some heating adapters…). This is my smarthome central which i use also for my influxDB where i store my data.

What i have:
I store in the influxDB the data points of my modbus adapter which grabs the data out of my SH10RT PV-Converter.
this result in these dashboard:

As you can see, i only have the voltage and the current as a given value. I calculate the power from these value´s in the expression like $E.
So far so cool.

Now i want to know how much energy is produced by a single string over a day. or…how much difference have the two pv-strings day by day.
string 1 (is expression $E) ist the east-side string =the blue one
string 2 (is expression $F) ist the west-side string = the red one

When i try it with a new expression like $G with the reduce an sum of $E, i get a new value.

I dont get what i have to calculate to get a value of the day? i first thought that i have to use the MD or intervall data but i dont know how.

Please help me to calculate the cumulated amount over the day and to compare it with the other string.

Kindly regards DRU

There are a TON of power-consumption-per-day topics on this forum. I would do a search over the past few years. There are lots of sample queries on good threads with input from some very advanced influx users. They are all a little different depending on the flavor of your setup and desired outcome, but I bet you’ll find some useful stuff if you go digging :+1:

Hi! Thx for your Reply. How long should i go back for a answer?
It seems that you computer was stuck by the copy paste function of the beginning of your answer. your answer can be found in several threads.
Every time the rest of your begun message (containing a hint or an answer) is missing.
Can you please add the answer to my question how to use calculated values for a further function in the same dashbord or an other dashboard.

Thx a lot!