DESS blocks feed-in when battery is full – contradicts Green Mode description

Q&A and troubleshooting DESS
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1

Hi everyone,
I’m using Dynamic ESS in Green Mode, with AC and DC feed-in enabled, and an additional Fronius inverter in a DC/AC-coupled setup.

The issue:
As soon as the battery is full, PV production (MPPT + Fronius) is curtailed, and no feed-in to the grid occurs – even though Green Mode explicitly states that surplus solar should be sold to the grid:

“Sell surplus solar power back to the grid after covering your consumption and charging the battery.”

If I disable DESS, everything works as expected:
→ The battery stays full, and all remaining PV is fed into the grid.
As soon as I enable DESS again, the system only supplies house loads, and excess solar is lost.

I would like the system to:

  • Keep the battery active (charging/discharging according to needs)
  • Still allow full feed-in when the battery is full, just like when DESS is off

Is this behavior intentional, or is there a bug or missing setting?

------------------------EDIT------------------------

MAybe I had to less informations. Here´s something more.
Here´s a screenshot from now today (9.a.m) with DESS off:

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This screesnhot is with DESS on:

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Weird? isn´t it? Why is the system cutting of the AC surplus? Before it was feeding in the grid. And when battery is full, the MPPT will also be cut off.

Here´s the setting from DESS:

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Do you need more informations? So please let me know I´ll post it right away. It´s important for me to know. So I think it´s a misadjustment in the settings. But I don´t know how to get things sorted or analyzed any further without your help guys.

------------------------EDIT------------------------
Here´s a screenshot from now today 1p.m with DESS off:

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This screesnhot is with DESS on:

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Now you can see, battery 100% AC-/DC-surplus is cut off unfortunately, while I could feed into grid approx. 13kW… :frowning:

In the meantime I was reading through some posts in the community here, and several persons have same issues but it´s not solved. So is this a major problem?
Thanks in advance!

2

In your DESS settings you set “Can you sell energy back to the grid” to “No”, then DESS throttles PV power, because there’s no point to feed-in the power.
Set that setting to “Yes” and review other settings. Don’t forget to set maximum export power if your utility provider limits it.

3

Hi Nani,

can that be true? As I´ve thought a configuring problem from myself. I thought this point is related to the battery in terms of reselling to the grid. Because here in Germany it´s forbidden to to that. I turned it on and what shall I say…it´s working.
Thank you very much for this hint!

Kind regards

4

For battery restrictions there’s another setting. I think DESS can do this now with the latest update that enabled Dynamic power limiting on PV inverters.

This is the setting you’re looking for, DESS → Battery (this prohibits discharging the battery to grid while allowing PV power to export)

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5

Hi Nani,
yes that´s absolutely correct. This was already activated in my settings.
So my fear to do something illegal was totaly arbitrary.
Anyhow, thank you very much!

Kind regards.

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