This section details the MQTT messaging format and payload requirements for remotely controlling power policies on devices within the SmartGrid network.

MQTT Topic

The MQTT topic used for sending commands is structured as follows:standard1/rp_one_s/remoteControlMetrics/<SmartGrid One SN>

Where <SmartGrid One SN> should be replaced with the actual serial number of the SmartGrid device you intend to control.

MQTT Payload Structure

Commands are sent as JSON payloads. The payload structure is designed to specify various power management policies and setpoints for different components of the smart grid system. Here is the outline of the payload with detailed field descriptions:

{ "extraTags": { "nodeId": "<SmartGrid One SN>_site_0" }, "time": "<Unix Timestamp>", "fields": { "<Component Policy>": "<Policy Type>", "<Component Power Setpoint>": <Setpoint in watts> } }

Fields Description

extraTags (Object):
- nodeId (String): A unique identifier for the node within the SmartGrid network. This is equal to your serial number, followed by '_site_0' for most SmartGrid One devices.
time (Integer): Unix timestamp in seconds indicating the time when the message is sent.
fields (Object):
- <Component>_policy (String): Policy type for the component. It is optional and if not specified, the system will fallback to the controller's default setting.
- <Component>_power_setpoint_w (Float): Desired power setpoint in watts for the component. This is optional and only relevant if a corresponding policy is specified.

Components and Policies

Each component in the fields object can include a policy and a power setpoint. The following components can be controlled:

solar_policy and solar_power_setpoint_w:
- Controls the solar power generation policy and setpoint.
  Supported policies:
  - Policy setpoint: Set the maximum power produced by all connected solar installations combined. Field solar_power_setpoint_w should be set to the production power limit in watts.
  - Policy cost: Enables day-ahead price (EPEX Spot market) cost minimization on the solar production. When negative injection prices occur, we curtail production to own consumption. When both the offtake and injection price are negative, we switch off all solar installations. Field solar_power_setpoint_w is ignored.
  - Policy self-consumption Produce at full power. Field solar_power_setpoint_w is ignored.
  - Policy off: Disables all interaction for all solar assets. Warning: limits are not being guarded in this mode. Field solar_power_setpoint_w is ignored.
storage_policy and storage_power_setpoint_w:
- Controls the energy storage system policy and power discharge or charge rate.
  - Policy setpoint: Set the total charge power (positive setpoint) or discharge power (negative setpoint) for the group of batteries. When multiple batteries are attached, then the setpoint is split up by available charge/discharge power to equally stress the batteries. Field storage_power_setpoint_w is set to the desired battery power.
  - Policy cost: Enables day-ahead price (EPEX Spot market) cost optimization on the batteries, by charging it on the cheap hours and using the energy in the expensive hours. Field storage_power_setpoint_w is ignored.
  - Policy self-consumption Enables a simple self-consumption algorithm on the batteries. Excess solar production is stored to the battery during, and when the sun is down, energy is taken from the battery. Field storage_power_setpoint_w is ignored.
  - Policy off: Disables all interaction for all battery assets. Warning: limits are not being guarded in this mode. Field storage_power_setpoint_w is ignored.
heat_pump_policy:
- Toggles on/off heatpump systems. The minimum and maximum on times will always be respected.
  - Policy cost: Enables day-ahead price (EPEX Spot market) cost optimization on the heat pumps. The local dynamic pricing algorithm decides the best on-time periods
  - Policy self-consumption Turns on the heat pumps if an excess of solar energy is produced.
  - Policy power_off: Power off the heat pumps.
  - Policy power_on: Power on the heat pumps.

switched_load_policy:
- Toggles on/off relay-controlled systems. This could be the built-in relay or network-connected relays.
  - Policy cost: Enables day-ahead price (EPEX Spot market) cost optimization on the relay.
  - Policy self-consumption Turns on the relay if an excess of solar energy is produced.
  - Policy power_off
  - Policy power_on

variable_power_load_policy and variable_power_load_power_setpoint_w:
- Manages the electric vehicle power consumption policy and setpoint.
  - Policy setpoint: Set the total charge power for the group of EVs. Field variable_power_load_power_setpoint_w is set to the desired charge power.
  - Policy cost: Enables day-ahead price (EPEX Spot market) cost optimization on the batteries, by charging it on the cheap hours. Field variable_power_load_power_setpoint_w is ignored.
  - Policy self-consumption Enables charging if an excess of solar energy is produced. Field variable_power_load_power_setpoint_w is ignored.
  - Policy off: Disables all interaction for all EV assets. Field variable_power_load_power_setpoint_w is ignored.

Fallback Behavior

For each component, if the _policy and _power_setpoint_w is not specified, the system will automatically use the fallback policy configured in the controller. This ensures that each device or device group operates safely and continues to function even if specific instructions are not provided.

If no command is being send at all, after 60 seconds (or configured timeout period), the default policies for assets will be reactivated.

Example Payload

Below is an example of a payload to set various policies and setpoints:

{ "extraTags": { "nodeId": "OM12404080000000000_site_0" }, "time": 1714652046, "fields": { "solar_policy": "setpoint", "solar_power_setpoint_w": 5000, "storage_policy": "setpoint", "storage_power_setpoint_w": -5000 } }

In this example, the solar power is set to generate up to 5000 watts, and the energy storage system is set to either charge or discharge at a rate of 5000 watts, depending on the sign of the setpoint value. If either the solar_policy or storage_policy were omitted, the respective device would revert to the default settings determined by the controller.

Fox ESS H3

Models