Wind turbines, water turbines and gensets

The Sunlight Group EMS supports wind turbines and water turbines (run-of-river hydro) as production devices, next to PV. A turbine is controlled like a PV inverter: the Sunlight Group EMS sends it a production limit, never a consumption setpoint. The difference is that a turbine does not depend on the sun, so the Sunlight Group EMS controls and monitors it around the clock.

This page explains how a turbine is added, how it is controlled, which external signals and alarms apply to it, and how backup power generators are handled.

Supported equipment at a glance

Use the sections below for turbine connections, turbine control and backup power generators.

Adding a turbine

There are two ways to bring a turbine into the Sunlight Group EMS: as a device, so that it can be controlled, or through an energy meter, so that its production is measured.

As a device

The device wizard on the "Devices" tab has a Wind turbine and a Water turbine tile (see Adding a device).

For a direct connection, use a compatible turbine integration. The Custom Modbus drivers module supports wind and water turbines over Modbus TCP or Modbus RTU (RS485). It can read production measurements and, if the turbine provides a writable power-limit interface, send a maximum production power. A monitoring-only integration does not provide curtailment.

To create this connection, use the manufacturer's register map to define the measurements and supported control operations, then test the integration before adding the turbine. Follow the Custom Modbus drivers guide for the editor, connection settings and testing workflow. If a new integration is needed, use New integrations and include the manufacturer's protocol documentation.

With an energy meter

For production monitoring without a direct turbine connection, use a compatible energy meter on its feeder:

1. Add the energy meter like any other energy meter (see Supported devices).
2. Open the device settings of the meter and answer "What does the energy meter mainly measure?" with Wind turbine or Water turbine. Keep Energy production for meters that measure PV.

The production of such a meter counts as production of the site: in the production, self-consumption and export figures, and on the data analysis page of the commissioning interface, where the "Solar" labels become "Production" as soon as the site has a producer that is not PV.

An energy meter only measures. The Sunlight Group EMS cannot limit a turbine that it only sees through a meter, the meter gets no no-production alarm of its own, and it does not count for the license. It also does not change how batteries are run at night (see Batteries at night): what a meter measures is entered by hand, so only a turbine that is added as a device makes the Sunlight Group EMS expect production at night.

Turbines that were added as PV inverters

On older sites, a turbine whose inverter speaks the protocol of a PV inverter may have been added with a PV inverter driver. Such a device is handled as PV, not as a turbine: the around-the-clock behaviour described on this page only applies to devices that are added as a wind or water turbine. The Negative price wind control mode can still be applied to them.

Device settings

Besides the name and the phase settings that many devices have (see Device settings), a wind or water turbine has one setting on the "Devices" tab:

Like PV inverters, turbines have no priority setting.

Control

Working mode

Turbines follow the default working mode for production devices on the Settings page, the same one as the PV inverters (see Setting control modes):

• Don't control: no active control.
• Cost optimization: production is switched off at negative purchase prices (you are then paid to consume), and limited to the consumption of the site at negative selling prices (you pay to inject your surplus). At other times, production is limited to the allowed grid export power.
• Feed in restriction till allowed grid export power (default): production is limited to the allowed grid export power.
• Control exclusively through external API: production is only limited by external control signals.

The difference with PV is the time of day. At night the Sunlight Group EMS leaves PV inverters alone, because they do not produce. A turbine keeps being controlled at night, so the export limit and the negative prices are also respected at night.

There is no dedicated wind or water production forecast: the Sunlight Group EMS reacts to the production that the turbine measures.

Batteries at night

In battery cost optimization, part of the battery is kept as a self-consumption variability buffer that absorbs excess production, and the setting "Preferentially store excess production immediately in the battery" charges excess production straight into the battery. On a site with only PV, both are only used by day, because there is no excess production at night. As soon as a wind or water turbine is added as a device, the Sunlight Group EMS knows that excess production can also occur at night, and uses both around the clock: excess turbine production at night is stored the same way as excess PV production by day.

A turbine that is only measured by an energy meter does not change this, and neither does a backup power generator.

Negative price wind control

The special local control mode Negative price wind control switches the selected wind turbines off while the purchase price is negative, and lets them produce at their nominal power the rest of the time. It can be applied to wind turbines and to PV inverters (for turbines that were added as PV inverters), not to water turbines.

External signals

A turbine is only controlled by the external signals that accept it. Every other external signal cannot select turbines: they keep following the default working mode.

• MQTT control: wind turbines and water turbines are their own device groups, wind and water, next to solar. They accept the same policies as solar, and a group setpoint is shared between the turbines of the group in proportion to their nominal power. See Live MQTT control.
• DNO Relay Control: when the input for curtailment is active, the PV inverters and the turbines are all limited to 0 W.
• Fluvius: wind turbines can be selected for both Fluvius signals. With V5, the allowed production power is shared between the PV inverters and the wind turbines in proportion to their nominal power. Water turbines cannot be selected, because Fluvius foresees no asset group for them.

Monitoring and alarms

No production

The e-mail alarm for missing production (see Email alarms) is named after the producers on the site, for example "Wind is not producing energy" or "PV or wind is not producing energy", and the e-mail says which device to check. A turbine is only checked when it is added as a device and has a nominal power.

When a device counts as not producing depends on what it is:

A device counts as producing from 1% of its nominal power. As for every e-mail alarm, the problem must persist before a mail is sent.

Following the production limit

A turbine is judged like a PV inverter by the alarm "Device not following the power setpoint or limit": the production limit is a maximum, so only producing more than the limit is reported. Producing less, for example because there is little wind, is not an error.

Testing a turbine

The Test / manual override action on the "Devices" tab tests a turbine with a production limit, like a PV inverter (see Testing and manual override). A limit can only be observed while the turbine produces: test on a moment with enough wind or water flow. When the turbine produces less than 100 W, the test page warns that there is not enough production to test curtailment. The automatic test procedure tests "Limit production to 15%" and "Limit production to 0%", and skips these tests when there is no wind or no water flow at the moment of testing.

License

For the license, the nominal power of a wind or water turbine counts like the nominal power of a PV inverter. Energy meters and backup power generators do not count.

Backup power generators

Gensets are supported as Backup power generator production sources. To monitor a genset, add a compatible energy meter on its feeder and set What does the energy meter mainly measure? to Backup power generator. The device wizard also has a Backup power generator category for compatible device integrations.

The generator device itself is monitoring-only: the Sunlight Group EMS does not send it a variable-power setpoint or production limit, and the "Devices" tab shows "Control is not supported". Its nominal power only serves the site overview. Relay start/stop is a separate function, configured through the low-battery-state-of-charge mode linked below; it does not regulate how much power the generator produces.

• Its production counts as production of the site. On a site with a generator, the data analysis page splits the production of the site into "Solar, wind and water production" and "Generator production".
• A generator does not make the batteries expect production at night: it runs on demand, for example during an outage, not on excess production.
• A generator gets no no-production alarm and no setpoint alarm, but it is still checked for missing measurements.
• To start a generator with a relay when the batteries run low, see Switching on a generator at low battery state of charge.