ESS - Energy Storage System

Important

This information pertains specifically to the 'Dual Tracker' model (PMR482602020).

Grid feed-in using an Energy Storage System is not supported by the older 'Single Tracker' model (PMR482602000).

An Energy Storage System (ESS) is a specific type of power system that uses the Multi RS to work in conjunction with a grid connection. It is used to optimise the use of solar power, battery storage and grid import or export.

ESS can be configured to optimize self-consumption or to keep batteries charged.

When there is more PV power than is required to run loads, the excess PV energy is stored in the battery. That stored energy is then used to power the loads at times when there is a shortage of PV power. When the battery is full, then the excess PV energy can be exported to the grid.

You can choose how much battery capacity you want to keep in reserve. If your grid connection is reliable, you can use more of the battery and keep less in reserve. Conversely, if your grid connection is unreliable and experiences frequent outages, you may prefer to keep more battery energy in reserve.

The “Keep batteries charged” option keeps the batteries fully charged whenever possible. The batteries will only discharge during a grid outage when solar power is insufficient. As soon as grid power returns or sufficient solar power is available, the batteries will recharge automatically.

Note

Do not apply ESS settings in systems with a generator. See the Generator programming section when a generator is connected at the AC input.Generator programming

The Multi RS can be configured as an Energy Storage System. In this setup, the device functions in grid-parallel mode, allowing energy to be sent back to the grid through the AC input terminals.

Note

For the Multi RS all ESS settings are configured in VictronConnect. There are limited configuration options in the ESS menu of a GX device.

To feed into the grid, you must select the appropriate grid code for your country within VictronConnect. In most cases, permission from the grid operator will be required before configuring an Energy Storage System to feed in.

If you do not have permission from your grid operator or if the installation does not meet the requirements for grid feed-in, set the grid code to 'None.' In this case, energy will not be fed back into the grid.

Important

Grid feed-in certification varies by country for the Multi RS, and it is not currently certified in all countries.

Do not assume the Multi RS is certified or permitted for grid export in your country simply because its grid code is listed in the drop-down.

Always check for current certificates for this product. These are available in the Downloads & Support section of the website.

Use VictronConnect to configure the Multi RS for ESS as below:

From the main settings page select the ESS settings page.

ESS mode: Tapping the box will display a selection of ESS modes. For an energy storage system, one of the optimized modes is typically the best choice. In this example, "Optimized without battery life" may be most suitable for lithium battery chemistry.
For more information on the other available ESS modes, visit the VictronConnect section.ESS
Minimum discharge SOC: This setting determines the lowest point at which the battery will be discharged when the grid is available. If the grid goes offline, the battery may continue to discharge below this level in order to keep the AC output powered.
Self-consumption from battery: You can choose whether the energy from the battery will power just the critical loads at the AC-out terminals or to also include loads positioned between a grid energy meter and the AC-in terminals.
Note
This option will only be visible if "Energy meter support" is enabled. See Connecting an external energy meter.
Without a grid energy meter, ESS can only supply the critical loads with battery power.

Self-consumption from battery options:

All system loads: ESS will use battery power to supply loads which are connected between a grid energy meter and the AC-in terminals, as well as critical loads connected to the AC-out terminals.
Only critical loads: ESS will only supply battery power to the critical loads connected to the AC-out terminals.
Loads connected between a grid energy meter and the AC-in terminals will be supplied by the grid and not from the battery.

Note

Grid code settings require a password for protection against unauthorized interference.

After setting a grid code for the first time, it cannot be deactivated or modified without a password. If you need assistance changing your grid code, please contact your installer.

Navigate to the Grid settings page, choose an appropriate grid code for your area, and select it. Depending on your selection, additional options may become available, which may vary by region. In this example, we will use Germany as the selected grid code.

Certain settings will appear greyed out and cannot be modified without setting the grid code password. Beware not to alter these settings unless instructed by your grid operator.

Grid code: Choose the country or region that corresponds to your installation's location.
Important
Always check that the Multi RS is certified for use in your country. The drop-down list does not imply certification. Check for certificates here.
Specs Tapping 'Show' displays the details and requirements related to the selected grid code.
Password: Installers have the ability to make additional changes and alter the grid code region by entering the password, but it's essential that you only modify settings as directed by your grid operator.

Loss of mains detection: Most of these settings are typically greyed out and are intended for informational purposes only. The values are defined by the selected grid code.

Use Aux1 as disable FeedIn signal: A grid operator may require a means to disable feed-in. To accommodate this requirement, installers can wire a contact to Aux1 of the Multi RS to disable feed-in as needed.
Use Aux 2 as limit charger signal: When using the Germany grid code, there might be a requirement from the grid operator to limit the charging power to 4.2kW divided evenly over the number of units. To meet this requirement, you can wire a contact to Aux2.

NS Protection log: The network system protection log records the five most recent protection events. Tap "Show" to view any logged events.

Feed-in configuration.

Feed-in allowed: This feature is designed to enable or disable excess energy flow into the grid, depending on your location's specific requirements. By default, it is set to 'on' (energy can be fed in), but if feed-in is not allowed, it should be toggled off.
Limit system feed-in: If you have a limit on the amount of energy that can be fed back into the grid, use this feature to set the maximum allowed feed-in power.
Maximum feed-in: Set a maximum limit for the amount of energy that can be fed back into the grid through the Multi RS.
Feed-in not active: Use this feature for diagnostic purposes when you notice that energy is not being fed back into the grid. Tapping the 'Check reason' button will display a list of potential reasons for the problem.

If the grid code requires external control of charging power or to disable grid feed-in, the contacts can be wired to the Aux_IN terminals of the User I/O connector.

Three-phase systems require contact wiring to only one unit’s I/O connector. The contact state is then shared with and replicated by all other units in the system.

Note

Not all grid codes support the use of Aux inputs.

As an example, for the German grid code, the Aux_IN terminals are used as below:

Contact A is wired to Aux_IN1+. When the external contact is closed, grid feed-in will be disabled.
Contact B is wired to Aux_IN2+. When the external contact is closed, the charging power from the grid will be limited to 4.2kW.

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Multi RS