Growatt Modbus Integration

A Home Assistant custom integration for reading real-time PV1 data from Growatt solar inverters (tested with Growatt 2000 TTLX with a ShineWiLan-X2 Wifi dongle) via Modbus TCP at a frequency of between 5 seconds and any value you want.

This is an alternative to getting these values from the default "Growatt Server" integration available in Home Assistant since this integration defaults to a minimum of 5 minute update interval via the Growatt API (this is a limitation of the Growatt API server).

Features

Real-time monitoring of voltage, current, and power from your Growatt inverter
Configurable update interval — adjust how often data is fetched (default: 5 seconds)
Last-known values — sensors display the most recent successful reading even if the inverter is temporarily unavailable
Automatic retry — connection failures trigger automatic reconnection attempts
Multiple inverter support — add multiple inverters with different configurations
Debug sensor — view raw data and diagnostics

Requirements

Home Assistant 2026.1 or later (tested with 2026.4.x)
Growatt inverter with Modbus TCP enabled
Network connectivity between Home Assistant and the inverter

Installation

Manual Installation

Download the files from https://github.com/tgip/hass_growatt_modbus
Copy the growatt_modbus folder to your custom_components directory:
~/.homeassistant/custom_components/growatt_modbus/
Restart Home Assistant:
Settings → System → Restart
Add the integration:
Settings → Devices & Services → Add integration → Growatt Modbus

Configuration

Basic Setup

Go to Settings → Devices & Services
Search for and click on Growatt Modbus
Click Add entry
Enter the following information:

Device Name: A friendly name for your inverter (e.g., Growatt)
Host: IP address of your Growatt inverter (e.g., 192.168.1.100)
Port: Modbus TCP port (default: 502)
Unit ID: Modbus unit ID (default: 1)

Advanced Configuration

You can optionally override default settings:

Option	Default	Description
Registers	[3, 4]	Modbus register addresses for voltage (3) and current (4)
Monitor Interval	minimum default 5 seconds	How often to fetch data from the inverter
Timeout	default 5 seconds	Modbus connection timeout

Finding Your Inverter's IP Address

Log in to your router's admin interface
Check the connected devices list
Look for your Growatt inverter's hostname (usually contains "Growatt")
Note the IP address

Enabling Modbus TCP on Your Inverter

Access your inverter's web interface (usually at http://<inverter_ip>)
Log in with your credentials
Navigate to Settings → Communication → Modbus TCP
Enable Modbus TCP
Note the port (usually 502 or 8899)
Restart the inverter

Sensors

Once configured, the following sensors are automatically created:

Sensor	Unit	Description
sensor.growatt_voltage	V	PV1 input voltage
sensor.growatt_current	A	PV1 input current
sensor.growatt_power	W	PV1 input power (calculated as voltage × current)
sensor.growatt_debug_data	—	Debug sensor with raw register data

Example Automation

Monitor when power drops below 100W:

automation:
- alias: "Growatt Power Low"
 trigger:
   platform: numeric\_state
   entity\_id: sensor.growatt\_power
   below: 100
 action:
   service: notify.notify
   data:
     message: "PV power is below 100W"

Example Template Sensor

Create daily energy totals in configuration.yaml:

template:
  - sensor:
      - name: "Growatt Daily Energy"
        unique\_id: growatt\_daily\_energy
        unit\_of\_measurement: "kWh"
        icon: mdi:solar-power
        state: "{{ states('sensor.growatt\_power') | float(0) / 1000 }}"

Troubleshooting

Integration Won't Set Up

Error: "Could not connect to inverter"

Verify the inverter's IP address is correct
Confirm Modbus TCP is enabled on the inverter
Check that the port number is correct (default: 502)
Verify network connectivity between Home Assistant and the inverter:

ping <inverter\_ip>

Check Home Assistant logs for more details:

Settings → System → Logs

No Data / Sensors Show Unknown

Error: "Modbus error ... Using last known values"

Verify the Modbus register addresses are correct for your inverter model
Check that the Unit ID matches your inverter configuration (usually 1)
Increase the Timeout value if you have a slow network
View the debug sensor to see raw register values:
    Go to Developer Tools → States
    Search for sensor.growatt_debug_data

Connection Drops Frequently

Increase the Timeout value (try 10 seconds)
Check network stability between Home Assistant and the inverter
Verify the inverter isn't overheating (check inverter logs)
Move Home Assistant closer to the inverter or improve network connectivity

Debug Sensor Shows No Data

The debug sensor displays OK when readings are successful and stores raw data in extra_state_attributes. To view:

Go to Developer Tools → States
Click on sensor.growatt_debug_data
Expand the attributes section to see voltage, current, and power values

Register Reference

By default, the integration reads from:

Register 3: PV1 voltage (0.1 V scaling)
Register 4: PV1 current (0.1 A scaling)

For other Growatt models, consult your inverter's Modbus documentation to find the correct register addresses. Common Register Addresses

Data	Typical Register	Scaling
PV Voltage	3	0.1 V
PV Current	4	0.1 A
PV Power	5	1 W
Grid Voltage	35	0.1 V
Grid Frequency	37	0.01 Hz

Performance Notes

Update interval is set to 5 seconds by default — reduce this if you need faster updates, but be aware this increases network traffic
The integration retains last-known values if the inverter is temporarily unavailable, preventing sensor gaps
Connection failures trigger automatic retry with exponential backoff
All Modbus reads use short timeouts (default 5 seconds) to prevent Home Assistant from hanging

Contributing

Found a bug or want to improve the integration? Feel free to open an issue or submit a pull request.

License

This integration is provided as-is for use with Home Assistant.

Support

For issues specific to this integration, check the Home Assistant Community Forums.

For Growatt inverter support, consult your inverter's manual or visit the Growatt website.