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Donald Polzin avatar image
Donald Polzin asked

Standard configuration for ESS meter impossible

Hi,

I am planing for an AC coupled ESS configuration with grid-tied PV inverters. I have 2 design goals, the ESS storage shall be charged by PV excess power only and the stored energy shall flow into the private loads only (i.e. the ESS Multi shall produce a bit less than private load consumption).

Problem comes into play with the standard ESS configuration, in particular placement of the ESS meter. I made a sketch to describe the problem and an alternative solution approach.

As I have seen from the ESS design guide, the CCGX appears to have only input for one ESS meter, which would not support the alternative solution approach.

Any clue, good idea or advice to make it happen?

BR Donald

210115-alternative-ess-meters-configuration.png

ESS
210115-alternative-ess-meters-configuration.png (241.2 KiB)
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2 Answers
Rob Duthie avatar image
Rob Duthie answered ·

Hi

You have to install it at the point after the utility meter for the system to work correctly, you need to reroute your cables to do this, it wont be that hard as some one already installed the Victron and Fronius at some point in the supply?

Regards

Rob D

NZ

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Donald Polzin avatar image
Donald Polzin answered ·

Hi Bob,

thanks for comment. No, there is nothing installed besides the PV inverter (CONERGY) and the utility meters / lines.
In DE the utility stuff is placed within a small, sealed cabinett without extra space for a meter. You are not allowed to open it. Complicated process to implement changes, would require to involve the utility.

The ESS is to come ... I hope someone has a clue how to make the sketch with 2 meters working.

BR Donald

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Rob Duthie avatar image Rob Duthie commented ·

Hi Donald

You can use the 2 energy meters where you have them and configure then as a grid and PV meter in the settings, not as good as single meter measuring all the power flow, but will work OK. What country are you from? In general you should access to the grid tied inverter wiring as this is you equipment and also the grid feed into your house.

Just the added cost of 2 energy meter that's all.

Depends how big your loads are you could run the AC coupled on the output if the Victron and run a micro grid

We don't have those issues in New Zealand at all with grid access and metering?

ESS_design_installation_manual.pdf

Victron MultiPlus-II-to-MultiGrid-and-MultiPlus-comparison-EN wiring.pdf

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ess-design-installation-manual.pdf (664.7 KiB)
victron-multiplus-ii-to-multigrid-and-multiplus-co.pdf (2.0 MiB)
Donald Polzin avatar image Donald Polzin Rob Duthie commented ·

hmm, thought I'd typed something, again ...

looks fine, thanks Rob.

The PV is 20 KWp, will violate the 1:1 rule.

Mine 2 meters utility setup is standard in Germany (DE), because we have 3 tarifs, "excess fed-in" // "fed-in and purchased back for consumption" // "excess consumption purchased from utility".
I have access to the PV und load lines as sketched.

Missing link is the connection of the 2 meters. Are these MODBUS devices and can by daisy-chained to the meter port of the CCGX ...??? How is that configured to achieve the design goal, i.e. supporting PV energy only, nothing to/from utility.

Every ESS in Germany is monitored by a federal agency, I need to supply a config on VICTRON paper, which supports the design conditions.

BR Donald


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Rob Duthie avatar image Rob Duthie Donald Polzin commented ·

Hi

You don't violate the deign rule as you are on the input side to the Victron, it only applies if you are on the output of the Victron inverter,

Yes you can daisy chain buy setting the configuration of the energy meters Addressing code by using the Carlo Gavazzi application software and using a USB to RS485 interface to change one of the meters to a different ID address, and take not which one it is so you know if it is a PV meter or grid load meter.

Regards

Rob D

NZ

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