Fred
I was reinventing the wheel I think
As far as I understood your setup: you're reading out your inverters with another system and maybe also the in and out of the grid (use of or injection into) and put these information in openWB. With openWB you're commanding your wallbox and can choose to charge only with the excess of solar power.
The same setup for me: a PV installation, a go-echarger, for a long time vzlogger to read out my digital meter (in/out of the grid) that runs on a rpi0W. Lately a second rpi0W (to test first) with openWB and it workes fine. No readout at this moment of the SMA bluetooth inverters (2).
Previously the rpi0W to readout the meter was an old notebook with BT and SBFspot was running, Now I've to checkout why the raspbian doesn't want to find the BT hardware.
But instead of doing that I was looking for more flexibility of what I'd like to do with the follwing upcoming rules in mind (2021 or 2022)
The electricity distribution compagny want to change the billing and they will split the bill in 2 parts, one fix part and one part depending on the consumption.
And it's that fix part that bothers me. They want to bill it depending the max amount of grid use in a quarter of an hour. The max of each month will be used as an yearly average to calculate that fee with a minimum of 2,5kWh.
So with what I've now vzlogger and openWB I can't do a lot to reduce that bill especially in winter.
I should need a system where I can forecast the amount of sun a day and the next day will produce (solcast and your flows). Depending that forecast I've to use only sunpower or I can use sun and grid power but I want to limit the grid power (in) probabely 2,5kW, the minimum fee for the fix bill component.
Therefore I was looking to put everything in node-red, to be more flexible.
I already saw, not tested, a node for the digital meter, saw that SBFspot has the ability to send its info to MQTT.
Why are you still using openWB and did not put everything in node-red yet?
A small home battery will be needed in the future to help out the mentionned limit, but commandable battery inverters are rare at this moment.
BR
