Solar Passthrough

DIY
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1

Hello @all,

the solar part on my system is completely connected AC wise on ACout1 of my 3 MP5000.

Is there any easy way to passthrough the solar generated power to grid instead of setting the setpoint? Switching e.g. to inverter modes does not do it.

Thanks and best regards

Robinson

2

This is what ESS is for and enabling the exporting of power.
Have a read of the ESS design guide and the relevant sections of the PV inverter setup guide.

3

Set feedback excess from ac coupled pv in the ess menu.

4

Hi

and already thank you for your fast help! But my question seems to be misunderstood.

I of cause activated ESS on ACout. My question was, how I can passthrough the solar power within this setup.

My system charges the akku as long as more energy is available than I directly use. I can controll, if also a part of solar power is not going into akku but to grid by changing SetPointAC to e.g. -1000W.

If I want all solar power to grid before akku is fully charged, I have to regulate the SetPointAC dependently on the incomming solar power. So my question is if there is an easier way than to regulate SetPointAC.

Best regards

Robinson

5

You have to enable AC exporting of power in ESS, and make sure that your PV inverters are being controlled by the ESS assistant.
When your batteries are full it will feed back.
If you are trying to force exporting prior to this then you need to use a setpoint.

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6

I have a second (old DIY) battery and I use Node Red/MQTT to change the setpoints

“It is a master slave system”

7

If you want to feed in all energy from solar before the battery is at 100% you can manually set the „limit charge current“ to 0.

I use this to limit how fast my batteries are charged in summer.

8

If export is enabled that setting is ignored, as per the docs.

9

Weird. I have been setting „limit charge current“ to 100A for years to slow charge the battery.
With AC and DC export enabled all excess energy beyond the 100A was then exported to grid.
I will test that tomorrow in my environment.

10
  1. DVCC charge current limits are not applied to DC MPPTs when ESS is enabled with Allow DC MPPT to export. This is to get maximum output from the solar panels for export.
11

That is correct. But is that even if you manually set „limit charge current“ to Zero or a low number?

12

Yip. It is ignored by dc chargers. Like ccl =0, charge =0 is a bad idea and cannot be honoured.

13

Will test it as well

14

That is partially correct, it depends on the system layout.

When DC Feedin is enabled, the MPPTs will always run full power, so the battery will take whatever it can, before the multis feedin.

Thus, charge current limit “cannot be applied to DCPV”.

But if you set a limit of for example 50A and DCPV saturates that (or is above) the multis won’t additionally charge ACPV to the battery.

If in turn there is only 10A DCPV, multis will only top that up upto the configured 50A limit and feedin ACPV above.

Thus, on a ACPV-heavy system with little DCPV and a high enough chargecurrent limit it CAN apparently work.

Yes, tricky - so it’s easier to put a “No” in the docs :grinning_face_with_smiling_eyes:

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15

Indeed. So. Terms and conditions apply.

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16

Works for me, solves my problem.

Now I have to find, how I can change the current limit or completely swith limitation on/off by MQTT or ModBus - I prefere the the first. Will look for it the next days.

Thanks a lot!

Robinson

17

I use Nodered to get the solar forcast from VRM at 5am and then set the limit based on how much is coming in.

Edit for future reference:
To completly disable charge with a RS 6000 system you can use a custom control node in Nodered and trigger /Ess/DisableCharge with 0/1.

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