ESS design and installation manual

Optimized (with BatteryLife) and Optimized (without BatteryLife)

At times when there is excess PV power, the PV energy is stored in the battery. That stored energy is then used later, to power the loads at times when there is a shortage of PV power.

Keep batteries charged

Failures of the utility grid are the only periods at which the battery will be discharged. Once the grid is restored, the batteries will be recharged with power from the grid, and of course also solar, when available.

External control

The ESS control algorithms are disabled. Use this when self-implementing a control loop. More information.

BatteryLife

For details on BatteryLife operation, see Chapter 6.2. In short, enable BatteryLife for these technologies:

Because it makes no sense to leave a battery discharged, without reserve power in case of mains failure, we recommend leaving BatteryLife enabled on the following battery technologies, too:

However, BatteryLife can be disabled in these cases.

Select External meter if an external meter such as an EM540 is installed, otherwise leave the setting as Inverter/Charger.

All loads and (optional) grid-tie inverters must be installed on the AC out in a system without a Victron grid meter. See earlier in the manual for more information.

Setting this to 'Disabled' hides the AC-out graphic in the overview pane. Use this in systems where there is nothing connected to the output of the Multi or Quattro, which is typical for certain grid-parallel systems in Western Europe.

This setting allows ESS only to use battery power for essential loads. It also allows battery banks to be sized to get critical loads through the night without the battery being discharged into the non-essential loads.

This is relevant for ESS systems with:

Setting options are:

This menu item is only visible if 'Inverter AC output in use' is enabled.

Set to 'On' to make the solar charger always operate at its maximum power point. The first priority is powering the loads, and the second priority is to charge the battery. If more power is available when those two priorities are met, then that power will be fed to the utility grid.

Please note that when enabling this option, the DVCC charge current limit configured under Settings → Limit charge current won't be active. The solar charger will operate at full power for maximum feed-in into the grid. It's advisable to configure a safe limit on the solar chargers when used with a small battery bank.

See chapter 7.

Configurable minimum SoC limit. Either with or without BatteryLife enabled, ESS will drop loads once the SoC has fallen to the configured setting - except when the utility grid has failed and the system is in Inverter mode. In this case it will continue discharging the battery until one of the other thresholds have been met. See chapter 6.1 for more information.

(Applies only when BatteryLife is enabled - it is always on in 'Keep batteries charged mode')

Using the Peak Shaving option it is possible to always let the system keep PowerAssisting when the loads exceed the AC input current limit and it is required, or only above the Minimum SOC parameter.

As soon as the peak is over, it will recharge the battery using power from the grid, while still prioritising solar.

Note that there is a 5% hysteresis; If the Minimum SOC is set to 50%, it will then start recharging back to that 50% only once (by peak shaving) the battery has dropped to 45%.

Also note that this works for the critical loads on the AC output only, not those connected to an energy meter.

The default setting when using the Optimised modes is 'Above minimum SOC only.' Use this option in systems that do not perform peak shaving.

(Applies only when BatteryLife is enabled)

This % shows the maximum usable capacity of the system - which will never be more than 80%.

Use this setting to see the current BatteryLife SoC level.

The different BatteryLife states are:

Limit the power drawn by the Multi: ie. limit the power being inverted from DC to AC.

Notes:

This sets the point at which power is taken from the grid when the installation is in self-consumption mode. Setting this value slightly above 0W prevents the system from feeding back power to the grid when there is a bit of over-shoot in the regulation. The default value is therefore 50W - but should be set to a higher value on large systems.

The grid feed-in can be controlled via this menu. It enables the AC and/or DC-coupled PV feed-in to be completely deactivated or the maximum feed-in power to be limited.

Feed-in will only occur if there is sufficient surplus PV production to fully supply the loads, and the battery is charged (or at it's charge current limit).

The Feed-in limiting active status indicator shows 'Yes' only if the feed-in limiting is currently working. In all other cases, the status is displayed as 'No'.

Note: The limit system feed-in is a system target, and under some circumstances such as large load disconnection, or sudden increase in solar production, it may be exceeded momentarily until the system is able to regulate the inverter output back to within the target limit.

The AC-Coupled PV zero or limited feed-in feature is specifically designed and most rigorously tested with Fronius AC PV inverters.

Change the following settings in the Fronius web interface:

Note In Settings→DNO Editor, the default setting for Dynamic Power Reduction is 'No limit/off'. If you wish for the Fronius to stop generating if communications are lost (and no longer receiving instructions from Modbus control), then additionally "Dynamic Power Reduction" also needs to be configured.

For this behaviour - set Export Limitation to entireSystem, and DPL_SOFTLIMIT_POWERLIMIT to the export power limit (or 0).

Then double check that all above criteria are met. It will show Feed-in limiting active No if the firmware requirement; the Data export; or the Sunspec Model type settings are incorrect, or the units are shut down (no available PV), or AC-input is disconnected / unavailable.

When working correctly, Feed-in limiting active will show Yes

Do not use a Fronius Smart Meter for limiting export when part of a Victron ESS System. More details about when a Fronius Smart Meter can, and can not, be used is explained here.

The Scheduled charge levels setting is located in the ESS menu of the GX device. It allows you to set up to five scheduled periods, during which the system will take power from the grid to charge the battery. This is typically used to charge the battery during off-peak tariff time windows (TOU). For each schedule, configure a start time, the duration, a SoC limit (target) and the self-consumption limit behaviour.

How does it work?

By intelligently creating the charge slots, for example a scheduled charge slot with a lower SoC target following another slot with a higher SoC target, the system allows power from the battery to be used until it reaches the lower state of charge.

This also enables more flexible planning of the charge slots in the event of scheduled outages (load shedding schedules). For example, if there is a scheduled outage at 8pm and again at 4am, you can recharge after the 8pm outage, but not after the 4am outage (since the sun will be up soon and PV takes over).

Scheduled charge levels is available as part of ESS. It is accessible on the GX device menus under Settings → ESS. It is only available when the ESS mode is set to Optimised. Scheduled charge levels naturally makes no sense when the mode is set to Keep Batteries Charged.

You can see at a glance what is configured, with a summary of the start day, time and duration shown for each.

For each schedule you can select a specific day of the week, every day of the week, or you may opt to charge on all weekdays or only on weekends.

The Multi will start charging from the grid at the specified start time, and stop after the set duration or when the set SoC limit is reached. The period designated by the day, start time and duration will subsequently be referred to as a scheduled charge window.

During charging, the ESS state will indicate that Scheduled charge levels is in progress.

When a SoC limit is set for a scheduled charge window, charging will stop when the batteries reach the requested SoC.

Set the AC Input type to Generator when connected to a generator. The system will then enable generator-charging and correctly load the generator when running.

Note that we recommend wiring the Generator to AC-in 1, and the Grid to AC-in 2. The reason is that the Quattro will then prioritize the Generator over the Grid. That arrangement offers maximum flexibility (allowing forced generator intervention even when the grid is available) and maximises control.

More information on controlling remote generator start/stop is available here.