question

Jan Zmrhala avatar image
Jan Zmrhala asked

Peak shaving

Hello,

I have 30 kWp solar system with 3xvictron multiplus and 30 kWh battery. The setup is as follows:

  • grid offset is set to 50 (50 W are all the time taken from network)
  • all produced energy ist consumed in the object
  • the energy which is not consumed is saved in battery
  • when there is greater demand on consumption than the current PV productiion than is the electricty drawn from battery until the battery reach the minimum limit
  • when there is no solar and no capacity in battery, than all the electricity comes from network
  • ...

so classic setup.

I would like to use the system to watch the reserved capacity as follows:

  • on the regular operation as described above I would like to use max 50% of the battery capacity.
  • when there is enought power from PV and more then 50% of the battery than the system shoul have 50 W offset
  • when there is not enought power from PV and less then 50% of the battery than the system should use only the energy from PV and from grid until it approach the Reserved capacity limit (let’s say 5 k W)
  • When the consumption is for example 10 kW and the sun produce 3 kW than the system should be able to mantain 5 kW from network, 3 kW from PV and draw aditional 2 kW from the battery (also when the charge level is less than 50%). When the consumption drops to 2 kW than the battery should be charged from network or PV, but we need to keep the reserved capacity at maximum 5 kW (so when ther is no PV than the battery should be charged from network at rate of 3 kW - reserved capacity 5 kW should be not exceeded).

Is my point to you clear?

Is this possible?


system design
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3 Answers
Alexandra avatar image
Alexandra answered ·

Hi @Jan Zmrhala in short, yes most of what you desire is possible when the ESS assistant is programmed in on the inverter system and some settings customized through the ESS menu on the GX device in your system.

https://www.victronenergy.com/live/ess:design-installation-manual

Section 4 is specifically about settings. Section 6 about controlling depth of discharge using the GX.

Since you have 3 inverters in your system you would need someone who knows how to program the system correctly on the inverter system if they have not done so already.

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Jan Zmrhala avatar image Jan Zmrhala commented ·

Hi, I'm affraid there is no such setup in the article. If you know how peakshaving works please let me know how to set it up correctly. I will be very gratefull for 1phase system. You don't have to think of 3 phase system.

thank you

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Alexandra avatar image Alexandra ♦ Jan Zmrhala commented ·

@Jan Zmrhala

Once ess assitant is programmed into the inverter than the rest can be customised through the GX device you have in your system.

If you allow your system to use the batteries up to the 50% to assist pv with loads and set your grid point you can get the victron to provide the peak draws for your system and only switch to grid when there is no pv and the battery is at your lowest set level.

If you want to go into the evening with a higher SOC then you set a schedule in for charging

All of these options only appear if ess assistant is programmed in correctly

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Jan Zmrhala avatar image Jan Zmrhala Alexandra ♦ commented ·

Hello,


let me know your email adrress so I can add you to my system. You can then setup the peakshaving as folows:

  • on the regular ESS I would like to use max 50% of the battery capacity.
  • when there is enought power from PV and more then 50% of the battery than the system shoul have 50 W offset
  • when there is not enought power from PV and less then 50% of the battery than the system should use only the energy from PV and from grid until it approach 16A limit
  • When the consumption is for example 25A and the sun covers 5A (AC) than the system should be able to mantain 16A gird, 5A PV and draw aditional 4A from the battery (also when the charge level is less than 50%). When the consumption drops to 5A than the battery should be charged from network or PV, but we need to keep the input limit on 16A

thank you


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Alexandra avatar image Alexandra ♦ Jan Zmrhala commented ·

Hi @Jan Zmrhala It would be better for you to contact whoever installed your system or your local dealer. I would not be comfortable programing someones system without having being involved in design and physical installation. Also being able to set varying limits on amperage is not possible without system user input on the color control. There is a dynamic current limiter in software, but again can be done by someone on the ground your side.

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Jan Zmrhala avatar image
Jan Zmrhala answered ·

Hi,

I’m familiar with 3 phase systems and ESS setup. I need to solve peak shaving (using some battery capacity to do peak shaving), and the rest for normal ESS use.


In the link of your answer there is no such setup.

Thank you

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Alexandra avatar image Alexandra ♦ commented ·

@Jan Zmrhala You could try set the input current limit down on each phase.

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Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

Except the last point is everything pretty easy.

But the last point can become tricky.
You have to play around with some of the assistants like "charge current control"(to charge with only 3kW) maybe "input current limit control" idk.
If you set 50% as minimum SOC in the ESS settings of the GX device, there is no way to get 2kW from the batteries for your "10kW load scenario"

It can take hours or days to figure that out(if it is possible).

What Batteries do you have?

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Jan Zmrhala avatar image Jan Zmrhala commented ·

Hi, I have BYD batteries. It is possible to do peakshaving with victron?

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