Discharge stops solar

[stephenbennett-uk]

I have an issue which is probably very specific to my system - although it's possible some may have a similar problem.

I have an GivEnergy All-in-One and connected to the solar input of this system is another GivEnergy Hybrid Inverter. The hybrid has a 9kwh battery and solar panels.

Right now, my export is limited to 3.68kwh

If PredBat gives the command to export, the All-in-One always wins. It'll max out the Grid output. That's fine - except for when the 9kwh battery is full and the panels are still getting generated. The solar has nowhere to go, so it gets shut down.

When I handled this in a more manual way - before PredBat, I'd start exporting from the Hybrid system first. This would max out the line using solar and then topping up with battery. One I had some headroom, the All-in-One could start exporting.

Is there a way to give priority to the Hybrid system? Or stagger how the discharging happens?

[gcoan]

there's no really easy way of doing what you want fully in predbat as it controls all inverters in parallel, so when exporting is set, it will cycle round all configured inverters and set them all to export

one option could be that you only control your hybrid inverter through predbat, and create an automation to shadow activities in the AIO after a suitable delay, but this is a bit messy

another option is you use predbat_manual_api to set the discharge limit of the AIO to zero, and then write an automation to increase the discharge limit a period of time after export status has been set in predbat. You'd need to work out the transitions you want, i.e. when to throttle the discharge rate, when to set it to max, etc. You can change the discharge rate of the two inverters independently via this method

a third option is to set your hybrid as a givenergy inverter as normal in apps.yaml, but create the AIO as a custom inverter type https://springfall2008.github.io/batpred/inverter-setup/#i-want-to-add-an-unsupported-inverter-to-predbat
you can copy the GE inverter type definition in config.py so you get the inverter setup correctly
the key reason for doing this is that you can then define scripts that predbat will run to start and stop charging, discharging, etc. And in the discharge script you can add whatever delay you want

this last option is I think my preferred. Predbat has two inverters defined, GE and GE-AIO (for example), and the GE-AIO invokes custom scripts to give you the delay you want between the two inverters acting

[stephenbennett-uk]

For now, I've added an override that looks for exports when the hybrid battery is 100% and temporarily pull down the AiO export. That seems to do the job.

[Shirley676]

This sounds like a priority and sequencing issue between the two systems. If the Hybrid inverter could be configured to export first, it could use the available solar generation and battery capacity before the All-in-One starts exporting. That may help prevent the panels from being curtailed when the Hybrid battery is already full. It might be worth checking the available control settings or whether there’s a way to stagger the discharge between the two inverters. Hopefully, someone with a similar GivEnergy setup can confirm whether this is possible. I’ve also come across some useful information from one roof solar that may be worth checking.

[stephenbennett-uk]

I've added a little over-ride which looks at the state of the battery on the Hybrid system and when it's more than about 95% full, it pauses the AiO which allows the Hybrid to discharge and not throttle the panels. It seems to be doing the job :)