Export kWh

Hello - I am trying to create an export kWh total in emonpi. I have solar PV setup, “Type 2” with power 1 on meter tails and power2 on the Solar. I can’t see a way of doing it.

On my power1 input there is already a predefined import applied, allow positive-> log ->power to kwh. I want to do the opposite.

power1–> allow negative → multiply -1 → log feed : export → power to kWh

But if I add to the end of the processing list it wont work as at step 2 I have allowed positive only. I need BOTH import_kwh and export_kwh

So I then created a virtual feed:
power1 → allow negative → x -1
So I can now see my instantaneous export power, but there is then no option in dropdown “power to kwh”

I feel I am missing something obvious but I can’t see what?

The ‘trick’ is to add a process called ‘Reset to Original’ .

So after the 4th process step above the next steps would be:
Reset to Original
Allow Negative
Multiply by -1 to turn the negative value to positive
Log to Feed (export)

Perfect - all done THANKS!

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Just as an example of what I do (my situation may not match your requirements), here is a process I use:

I defined a PEAK period (3pm-9pm) because my imports are charged using two tariffs.
Might give you a few ideas.

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Thanks that’s useful - still learning I am more used to writing code that web front ends and moving processes up and down a list! So you can’t do multi-threaded processing on an input but resetting and doing sequentially is OK if the tasks are short which I guess they are.

At moment I am single tarrif, after 18 months of chasing my multi-tentacled energy supplier fitted a smart meter last month. Shortly after the PV went live Problem is it does not work, no display no network comms, both they & I are blind. (although I am assured is is actually measuring my use). As we enter week 4 of waiting to get it fixed I am both losing out on selling my surplus and they still charge me a monthly direct debit based on my pre PV use. I am trying to negotiate this down based on my emonPi data!

There’s a chance :smiley:
We had a user in the USA who was being overcharged - they got a refund based on OEM data.

It all done in PHP. The Input processes execute as the data is received. Each process is executed in sequence - top to bottom, the Input value enters at the top of the list and falls into the first process. That works on it and either passes a modified value out of the bottom, or sends the value or a modified one out to a Feed and passes the unmodified value down, to be picked up by the next process. (The blue ‘help’ note tells you).

Your problem was the original value had been modified, so you needed to start again with a reset. Equally validly, but maybe not what you wanted here, you could have reset to zero and then added the input - or even a different input.

Because of timing considerations, it’s generally better to add a Feed, rather than the corresponding Input.