Grid settings in ESS mode

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solartech12 asked Mar 1, '22

Grid settings in ESS mode

I have set SOC limit to 35% in a attempt for the grid to only charge my batteries once they go below 35%. to test that I turn on grid but It didnt work as expected. instead it was charging the batteries at 38% . why did it started charging even tho the limit (35%) wasnt reached?

Also what battery mode should I select for such operation? moreover how can I tell grid to stop charging my batteries at the desired battery voltage or SOC? basically i want to use grid only as a backup in extreme cases (i,e, below 35%)

also what does grid setpoint does?

ESS grid quattro 10kva

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Answer 1 · 2022-03-01T16:24:48Z

alexander-uhde answered · Mar 01, 2022 at 04:24 PM

Hi,

you should pick "Optimized(without battery life)" for your desired behaviour.

If you take "with battery life", as your screenshot shows, the system will use the "Active SoC limit", which is right now at 65% in your case.

Grid setpoint shows the average desired amount of power taken from, or transferred to the grid.

I.e. if you take 30 Watt, system will by default take 30 W from grid and try to take the rest from PV or batteries.

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solartech12 commented · Mar 01, 2022 at 06:35 PM

thanks for the info but at what soc level will the grid stop delivering? I mean when will inverter cut off grid power ? I want to use grid only when battery soc has fallen below 35% ( as in pic above) . so how I know when the grid will disconnect ?

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Matthias Lange - DE ♦ solartech12 commented · Mar 01, 2022 at 06:48 PM

ESS is always connected to the grid.

The system will stop using the battery at the set SOC.

https://www.victronenergy.com/live/ess:start

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solartech12 Matthias Lange - DE ♦ commented · Mar 01, 2022 at 11:41 PM

ok but when will it start using battery again ? if ESS is always connected to grid then when can I prioritize use of mppt over grid . also is grid code necessary when using ESS just for battery self-consumption ( in the case of Zero export/feed back to grid) ?

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Matthias Lange - DE ♦ solartech12 commented · Mar 02, 2022 at 05:04 AM

If the SOC rises 5% over the low SOC limit it will start using the battery again.

To charge the battery only surplus energy is used.

As long as enough PV power or battery capacity is available it will automatically have priority over the grid.

Please read the link above it will answer most of your questions.

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solartech12 Matthias Lange - DE ♦ commented · Mar 02, 2022 at 11:34 AM

thanks for sharing the link, I have already gone over it. my question is for ESS mode to able to work correctly , is there a need for grid code selection when I dont want any back feed into the grid?

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Answer 2 · 2022-03-02T06:41:41Z

elvis answered · Mar 02, 2022 at 06:41 AM

I'm pretty sure if your "Grid Set Point" is set too high and you are not using that much, its considered "Excess" and will charge your battery with the "Excess".

As in: "Grid Set Point" is 200 watts and you are only consuming 100 watts.

That other 100 watts will be used to charge your battery.

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solartech12 commented · Mar 02, 2022 at 11:31 AM

I have set it to be 220W just as starting point for the 10kva Quattro and 80kwh battery system, is it too much to start with ? also this grid setpoint will always take the value set in the settings regardless of what the current system state is?

Have a look at all these cases, I tested the grid for. also, I haven't put any grid code inside Quattro as my intention is not to back feed the grid. does it affect its working?

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