Fronius Solar Monitor 🌞⚡

This Python script monitors solar power data from a Fronius Inverter and sends Telegram alerts when the battery is full or no longer full. It can also control smart plugs based on battery status.

Table of Contents

• Overview
• How it Works
• System Requirements
• Installation & Setup
• Data Monitoring & API
• Additional Resources
• Troubleshooting
• FAQ

Overview

Fronius Solar Monitor helps you optimize your solar energy consumption by alerting you when your battery reaches full capacity or drops below it. Perfect for regions where excess energy fed to the grid isn't compensated beyond certain limits. You can also make changes and use it as part of your larger home automation system.

The system can automatically control Tuya-compatible smart plugs based on battery status, allowing you to automatically power devices (like water heaters, AC units, or pool pumps) when excess solar energy is available.

How it Works

1. Fronius Inverter provides real-time data via the Solar API (e.g., battery status, power consumption, etc.).
2. Fronius Solar Monitor Script retrieves this data using the API and evaluates the battery status.
3. Based on the readings, the script sends Telegram notifications (battery full or not) to the user.
4. Alerts are customizable based on frequency and consecutive checks, reducing false positives.
5. Smart Plug Control (optional) automatically manages connected devices based on battery status and/or PV production.

📋 System Requirements

• Supported Inverters: Fronius GEN24 series
• Operating System: Any Python-compatible OS (Linux recommended, Windows also ok)
• Python: 3.6 or higher
• Network: Local network access to Fronius inverter
• Smart Plugs (optional): Any Tuya-compatible smart plug

🔧 Installation & Setup

Prerequisites

• Python 3.x
• A Fronius inverter with Solar API
• Telegram account
• Tuya-compatible smart plug (optional)

Step 1: Install Dependencies

Install the required Python libraries using pip:

pip install requests  # Required for making API requests to the Fronius inverter
pip install tinytuya  # Required for smart plug control

Note: The tinytuya library is only required if you plan to use the smart plug feature.

Step 2: Enable the Fronius Solar API

The Solar API must be enabled on Fronius GEN24 devices to avoid 404 errors.

How to Enable:

1. Access the Fronius Web Interface

   • Enter your Fronius inverter's IP address in a browser.
   • Find the IP through:
     • Your router's device list
     • The IP configured during installation
     • Network scanning tools

   

2. Enable the API

   • Navigate to Communication → Solar API
   • Toggle the Solar API setting to enabled.
   • Save your changes.

   

Step 3: Create a Telegram Bot

A more detailed tutorial is available here.

1. Create Your Bot

   • Open Telegram and search for @BotFather
   • Send /newbot and follow the instructions.
   • Save the Bot Token provided.

2. Configure Chat ID

   • For a group chat: Add your bot to a group.
   • For a private chat: Start a conversation with your bot.
   • Send any message to the bot.
   • Get your Chat ID by opening:

     https://api.telegram.org/bot<TOKEN>/getUpdates
     

   • Note: Group chat IDs are negative numbers; private chat IDs are positive.

   

Step 4: Configure the Application

(more on the smart plug settings further down at Setting Up TinyTuya) Rename _config.json to config.json and configure it with your settings:

{
  "telegram_token": "6467835642:AAAAAl99Ue14-e2cPqF79KSdOol5-aTr123",
  "chat_id": "-1048737232455",
  "solar_api_ip": "192.168.1.131",
  "check_interval_min": 1,
  "consecutive_full_checks": 1,
  "consecutive_not_full_checks": 4,
  "language": "en",
  "smart_plug_mode": 1,
  "pv_threshold": 500,
  "smart_plug": {
    "enabled": true,
    "dev_id": "bfa03f282eff246980zuioe",
    "address": "192.168.1.230",
    "local_key": "?quej6(u$e<1<#<<",
    "version": 3.5
  }
}

Configuration Parameters:

Parameter	Description	Recommended Value
telegram_token	Your Telegram bot token	-
chat_id	Target chat ID for notifications	Negative for groups, positive for private chats
solar_api_ip	IP address of Fronius inverter	Local network IP of inverter
check_interval_min	Time between checks (minutes)	1-5
consecutive_full_checks	Readings needed before "battery full" alert	1-3
consecutive_not_full_checks	Readings needed before "battery not full" alert	2-5
language	Notification language	"en" or "de"
smart_plug_mode	Control mode for smart plug	1 or 2 (see below)
pv_threshold	PV production threshold in watts	500-1000 (depends on your devices)
smart_plug	Configuration for smart plug control	See below

Note: Higher consecutive_checks values reduce false alerts but increase notification delay.

Smart Plug Tip: Any Tuya-compatible smart plug will work with this system. These are widely available on AliExpress for around $5, making it an affordable addition to your solar monitoring setup.

Setting Up TinyTuya

To find your device ID and local key for the smart plug configuration, you can use the TinyTuya library. Visit the official TinyTuya repository for detailed setup instructions:

https://github.com/jasonacox/tinytuya

The repository provides tools to scan your network for Tuya devices, obtain device IDs, and retrieve local keys needed for the configuration.

Smart Plug Configuration

The smart plug feature allows you to automatically control a Tuya-compatible smart plug based on selected control mode.

Smart Plug Control Modes:

1. Mode 1: Battery Status Only (Default)

   • The smart plug will turn ON when the battery is full
   • The smart plug will turn OFF when the battery is no longer full
   • This is the original behavior

2. Mode 2: Battery Status + PV Production

   • The smart plug will turn ON only when:
     • The battery is full AND
     • Current PV production is above the threshold set in pv_threshold
   • The smart plug will turn OFF when either condition is not met
   • This mode helps ensure devices only run when there's sufficient ongoing solar production

Smart Plug Parameters:

Parameter	Description	Example
enabled	Enable/disable smart plug functionality	true or false
dev_id	Device ID of your Tuya smart plug	bfa5c4d187d5ab1234abcd
address	IP address of your smart plug	192.168.1.230
local_key	Local key for device authentication	a1b2c3d4e5f6g7h8
version	Protocol version	3.5

Testing TinyTuya Setup

To test if your smart plug is configured correctly, you can use the included test script that toggles the smart plug ON and OFF every 5 seconds:

python test_smart_plug.py

This is useful for verifying your smart plug connection and configuration before running the main monitoring script.

Step 5: Run the Monitor

Manual Execution

To run the script manually:

python solar_monitor.py

Automatic Startup on Raspberry Pi (DietPi)

For a headless setup on Raspberry Pi running DietPi or (maybe) also other Linux distributions:

1. Install DietPi: Download from dietpi.com.

2. Access via SSH in Terminal:

   ssh root@192.168.1.132  # Replace with your Pi's IP

3. Install Git and Python via dietpi-software (or your package manager if using a different Linux distribution).

4. Clone the repository and navigate to the project directory:

   git clone https://github.com/Persie0/Fronius-Solar-Monitor.git
   cd Fronius-Solar-Monitor

5. Verify the project directory: To ensure you're in the correct directory, run the following command:

   pwd

   If the output is not /root/Fronius-Solar-Monitor, you will need to update the PROJECT_DIR variable in the setup configuration. Edit the script to reflect the correct path.

   Example:

   nano /otherpath/Fronius-Solar-Monitor/setup_autostart.sh

   Update the line:

   PROJECT_DIR="/otherpath/Fronius-Solar-Monitor"

Then save with Ctrl+O, Enter and Ctrl+X.

6. Setup Auto-Start: Simply run the setup script included in the repository:

   sudo bash setup_autostart.sh 

7. Configure the bot: Edit the config.json file to include your bot's token, chat ID, and inverter's IP address.

   nano config.json

   then copy and paste your configured config.json into it. Then Ctrl+O, Enter and Ctrl+X.

8. Restart to test:

   sudo systemctl restart solar_monitor

   now you should already get a TG notification.

   Note: If you did not get an notification, to check for errors, run:

   tail -f /root/Fronius-Solar-Monitor/solar_monitor.log

   And if you really want to test it run:

   sudo reboot

9. Update to latest: To update to the latest version run in the Fronius-Solar-Monitor folder:

   git pull origin main

   After updating, restart the service:

   sudo systemctl restart solar_monitor

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📡 Data Monitoring & API

Example API Request

To verify connectivity with your Fronius inverter, you can test the API endpoint directly in your web browser: (Replace 192.168.1.131 with your inverter's IP)

http://192.168.1.131/solar_api/v1/GetPowerFlowRealtimeData.fcgi

Sample API Response:

{
  "Body": {
    "Data": {
      "Inverters": {
        "1": {
          "Battery_Mode": "battery full",
          "P": 4201.64,
          "SOC": 100
        }
      },
      "Site": {
        "P_Grid": 740.7,
        "P_Load": -4942.34,
        "P_PV": 4298.14,
        "rel_Autonomy": 85.01,
        "rel_SelfConsumption": 100
      }
    }
  },
  "Head": {
    "Status": { "Code": 0 },
    "Timestamp": "2025-02-18T14:50:13+00:00"
  }
}

Data Visualization

Web Interface

API Response Values Explained

Field	Description
Battery_Mode	Battery state (e.g., "battery full")
SOC	Battery state of charge (percentage)
P_Grid	Power from/to the grid (positive = importing, negative = exporting)
P_Load	Power consumption (negative values mean energy usage)
P_PV	Solar power generation
rel_Autonomy	Percentage of energy used from your own sources
rel_SelfConsumption	Percentage of solar energy used locally

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📚 Additional Resources

For detailed API documentation:

• fronius-json-tools
• Fronius Solar API Documentation (PDF)

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🛠️ Troubleshooting

Issue	Solution
404 Error when accessing the Solar API	Ensure the Solar API is enabled on your Fronius inverter and you're using the correct IP.
No Telegram message received	Double-check the Bot Token and Chat ID in config.json. Ensure the bot is correctly added to the group or conversation.
Data not updating	Make sure the inverter's IP is correct and accessible from your Python script. Test with ping or use curl to manually check if the API is responding.
Script Crashes	Run the script in debug mode by adding -v for more verbose logging. Check the logs in /var/log/solar_monitor.log for detailed errors.

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💡 FAQ

Q: Can I use the Solar Monitor with other inverters or smart plugs?

A: Currently, the Solar Monitor is designed for Fronius GEN24 inverters and Tuya-compatible smart plugs. However, you can adapt the code for other devices that provide API access:

For other inverters:

• Check if your inverter model has an available API
• Find the API documentation and endpoint structure
• Use the API URL and response format along with the solar_monitor.py script to modify the code (you can use AI tools like ChatGPT to help with the conversion)

For other smart plugs:

• Verify if your smart plug has an API or protocol that can be accessed via Python
• Find the required libraries and documentation for your smart plug
• Modify the smart plug integration code accordingly (AI tools can help with this adaptation)

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Happy Solar Monitoring! 🌞⚡