How To Setup MQTT And Connect With Home Assistant Solar Assistant Tutorial

🚀 Introduction

Congratulations on setting up Solar Assistant on your Raspberry Pi! You’re now monitoring your solar system in real-time. But why stop there?

By connecting Solar Assistant to Home Assistant using MQTT, you unlock a whole new world of possibilities:

✅ View solar data directly on your Home Assistant dashboard
✅ Create powerful automations that save electricity bills
✅ Track long-term energy statistics
✅ Control inverter settings remotely
✅ Get alerts on your phone for critical events

In this comprehensive guide, I’ll show you step-by-step how to connect Solar Assistant to Home Assistant using MQTT. No prior experience required!

🎯 What You’ll Learn

• What is MQTT and how it works (simple explanation)

• How to enable MQTT in Solar Assistant

• How to add MQTT integration in Home Assistant

• How to verify data is flowing correctly

• How to create a beautiful dashboard

• How to build your first automation

• Troubleshooting common issues

📋 Prerequisites

Before starting, make sure you have:

🤔 What is MQTT? (The Simple Explanation)

MQTT stands for Message Queuing Telemetry Transport. Sounds complicated? It’s actually simple!

Think of MQTT like a WhatsApp group:

• Solar Assistant sends messages to the group (publishes data)

• MQTT Broker (running on Solar Assistant) is the WhatsApp server that manages the group

• Home Assistant reads messages from the group (subscribes to topics)

When Solar Assistant sends a message like “Battery is at 80%”, all devices listening (like Home Assistant) receive that information instantly.

The Magic: Auto Discovery ✨

Solar Assistant has a special feature called Auto Discovery. This means:

1. Solar Assistant automatically tells Home Assistant:

   • “Here are all my sensors”

   • “Here are their names and units”

   • “Here’s what data they provide”

2. Home Assistant automatically creates all the entities for you!

No manual configuration needed! This is what makes Solar Assistant so powerful.

⚙️ Step 1: Enable MQTT in Solar Assistant

Let’s start by configuring Solar Assistant to act as an MQTT broker.

1.1 Access Solar Assistant Web Interface

1. Open your web browser

2. Type your Solar Assistant IP address (e.g., http://192.168.1.50)

3. You’ll see the Solar Assistant dashboard

1.2 Navigate to MQTT Settings

1. Click on Configuration tab (top menu)

2. Scroll down to the MQTT section

1.3 Configure MQTT Settings

Fill in these settings exactly as shown:

1.4 Save and Start

1. Click “Save” button

2. Then click “Start MQTT” button

3. Wait a few seconds for the service to start

✅ Verification: You should see a green “MQTT Running” status message.

🔌 Step 2: Add MQTT Integration in Home Assistant

Now let’s connect Home Assistant to Solar Assistant’s MQTT broker.

2.1 Open Home Assistant

1. Open your Home Assistant web interface

2. Log in if needed

2.2 Navigate to Integrations

1. Go to Settings (left sidebar)

2. Click on “Devices & Services”

3. You’ll see all your current integrations

2.3 Add MQTT Integration

1. Click the “Add Integration” button (bottom right corner)

2. In the search box, type “MQTT”

3. Click on “MQTT” from the search results

2.4 Configure MQTT Connection

A dialog box will appear. Enter these details:

2.5 Submit

1. Click “Submit”

2. Wait a few seconds for the connection to establish

🎉 Success! You should see a green success message: “Connected to MQTT broker”

✅ Step 3: Verify Data is Flowing

Now let’s confirm that Home Assistant is receiving data from Solar Assistant.

Method 1: Check MQTT Devices

1. Go to Settings → Devices & Services

2. Click on the MQTT integration

3. Go to the “Devices” tab

4. You should see your inverter listed (e.g., “FLIN Energy”, “Growatt”, “Luminous”)

5. Click on it – you’ll see 30-50 entities automatically discovered!

Method 2: Check via Developer Tools

1. Go to Developer Tools (left sidebar, under Settings)

2. Click on the “States” tab

3. In the search box, type “solar” or your inverter brand name

4. You should see all entities like:

sensor.solar_assistant_battery_state_of_charge
sensor.solar_assistant_pv_power
sensor.solar_assistant_load_power
sensor.solar_assistant_grid_power
sensor.solar_assistant_battery_voltage
sensor.solar_assistant_battery_current
... and many more!

What All These Entities Mean

🎯 Pro Tip: Negative values usually mean power flowing in the opposite direction. For example, negative grid power means you’re exporting to the grid!

📊 Step 4: Create a Beautiful Dashboard

Now for the fun part – displaying your solar data on a professional dashboard!

Option A: Simple Entities Card (Quick Start)

1. Go to Overview (left sidebar)

2. Click the three dots (top right corner) → “Edit Dashboard”

3. Click the “Add Card” button (bottom right)

4. Search for “Entities” and select it

5. Add these essential entities:

entities:
  - entity: sensor.solar_assistant_battery_state_of_charge
    name: Battery Level
  - entity: sensor.solar_assistant_pv_power
    name: Solar Generation
  - entity: sensor.solar_assistant_load_power
    name: Home Load
  - entity: sensor.solar_assistant_grid_power
    name: Grid Power
  - entity: sensor.solar_assistant_battery_voltage
    name: Battery Voltage
  - entity: sensor.solar_assistant_battery_current
    name: Battery Current
title: Solar Overview
type: entities

6. Click “Save”

Option B: Advanced Power Flow Card (Recommended)

For a professional, animated power flow diagram, install the Power Flow Card Plus:

Step 4.1: Install HACS (if not already installed)

1. Go to Settings → Add-ons

2. Click “Add-on Store” (bottom right)

3. Search for “HACS” and install it

4. Restart Home Assistant

Step 4.2: Install Power Flow Card Plus

1. Go to HACS (left sidebar)

2. Click on “Frontend”

3. Click “Explore & Download Repositories”

4. Search for “power-flow-card-plus”

5. Click “Download”

6. Refresh your browser

Step 4.3: Add Power Flow Card to Dashboard

1. Go to Overview → Edit Dashboard

2. Click “Add Card”

3. Search for “Power Flow Card Plus”

4. Paste this configuration:

type: custom:power-flow-card-plus
name: Solar Energy Flow
entities:
  entity: sensor.solar_assistant_battery_power
  solar:
    entity: sensor.solar_assistant_pv_power
  grid:
    entity: sensor.solar_assistant_grid_power
  load:
    entity: sensor.solar_assistant_load_power
  battery:
    entity: sensor.solar_assistant_battery_power
    state_of_charge: sensor.solar_assistant_battery_state_of_charge
invert_secondary: true
decimals: 1
watt_decimals: 1
color:
  mode: consistent
  battery:
    state_of_charge: true
  power_from_grid:
    state_of_charge: true
  solar:
    state_of_charge: true
    color_value: 80

5. Click “Save”

Result: A beautiful, animated diagram showing exactly how power flows between your solar panels, battery, home, and grid!

🤖 Step 5: Create Your First Automation

Now for the money-saving magic – automations!

Automation Idea: Turn On Geyser When Battery is Full

This automation turns on your geyser/water heater when:

1. Battery is above 90% (almost full)

2. Solar panels are generating significant power

3. It’s daytime (optional)

Step 5.1: Create New Automation

1. Go to Settings → Automations & Scenes

2. Click “Create Automation”

3. Click “Create New Automation”

Step 5.2: Set Trigger

trigger:
  - platform: numeric_state
    entity_id: sensor.solar_assistant_battery_state_of_charge
    above: 90
    below: 100

Step 5.3: Set Condition (Optional but Recommended)

condition:
  - condition: numeric_state
    entity_id: sensor.solar_assistant_pv_power
    above: 500  # Only if generating 500W+

Step 5.4: Set Action

action:
  - service: switch.turn_on
    target:
      entity_id: switch.geyser  # Replace with your geyser switch

Step 5.5: Save Automation

1. Give it a name: “Free Solar Geyser”

2. Click “Save”

Done! Now your geyser will automatically run on free solar power when the battery is full!

🔧 Advanced: Control Inverter Settings

If you enabled “Allow writing from Home Assistant” in Step 1, you can also control your inverter settings directly from Home Assistant!

Available Control Entities

Add Controls to Dashboard

1. Go to Overview → Edit Dashboard

2. Click “Add Card” → “Entities”

3. Add these select entities

4. They’ll appear as dropdown menus for easy control!

❗ Troubleshooting Common Issues

Issue 1: No Data Appearing in Home Assistant

Symptoms: MQTT integration shows “Connected” but no entities appear

Solutions:
✅ Check if Auto Discovery is ENABLED in Solar Assistant
✅ Verify username and password match exactly
✅ Try restarting both Solar Assistant and Home Assistant
✅ Check Solar Assistant logs for MQTT errors

Issue 2: Connection Refused

Symptoms: “Connection refused” error when adding MQTT integration

Solutions:
✅ Verify Solar Assistant IP address is correct
✅ Check if MQTT is started in Solar Assistant (not just enabled)
✅ Ensure port 1883 is not blocked by firewall
✅ Try pinging the Solar Assistant IP from your Home Assistant device

Issue 3: Some Entities Missing

Symptoms: Only some entities appear, others missing

Solutions:
✅ Some entities only appear when inverter is in specific modes
✅ Wait 2-3 minutes for auto discovery to complete
✅ Check if your inverter supports those specific data points
✅ Try restarting the MQTT service in Solar Assistant

Issue 4: Values Showing Wrong Units

Symptoms: Power showing in kW instead of W, etc.

Solutions:
✅ This is normal! Home Assistant automatically scales units
✅ You can adjust display settings in the card configuration

🎯 Next Steps: More Powerful Automations

Now that your solar data is in Home Assistant, here are some advanced automation ideas:

1. Grid Outage Alert

trigger:
  - platform: state
    entity_id: sensor.solar_assistant_grid_power
    to: "0"
action:
  - service: notify.mobile_app
    data:
      title: "⚠️ Grid Down"
      message: "Grid power failed. Running on battery!"

2. Battery Low Warning

trigger:
  - platform: numeric_state
    entity_id: sensor.solar_assistant_battery_state_of_charge
    below: 20
action:
  - service: notify.mobile_app
    data:
      title: "🔋 Battery Low"
      message: "Battery at {{ states('sensor.solar_assistant_battery_state_of_charge') }}%!"

3. Excess Solar Export Monitor

trigger:
  - platform: numeric_state
    entity_id: sensor.solar_assistant_grid_power
    below: -1000  # Exporting more than 1kW
action:
  - service: notify.mobile_app
    data:
      title: "💰 Exporting Power!"
      message: "Selling {{ states('sensor.solar_assistant_grid_power') }}W to grid"

4. Smart EV Charging

trigger:
  - platform: numeric_state
    entity_id: sensor.solar_assistant_battery_state_of_charge
    above: 95
condition:
  - condition: numeric_state
    entity_id: sensor.solar_assistant_pv_power
    above: 2000
action:
  - service: switch.turn_on
    target:
      entity_id: switch.ev_charger

📊 Energy Dashboard Integration

Home Assistant has a built-in Energy Dashboard that works perfectly with Solar Assistant!

Step 1: Configure Energy Dashboard

1. Go to Settings → Dashboards → Energy

2. Click “Add Grid Consumption” and select:

   • sensor.solar_assistant_grid_power (with negative values for export)

3. Click “Add Solar Production” and select:

   • sensor.solar_assistant_pv_power

4. Click “Add Battery System” and select:

   • sensor.solar_assistant_battery_power

   • sensor.solar_assistant_battery_state_of_charge

Step 2: View Energy Dashboard

Now go to Overview → Energy to see:

• 📈 Beautiful graphs of your energy usage

• 🔋 Battery charge/discharge history

• ☀️ Solar production vs consumption

• 💰 Grid import/export costs

🔐 Security Considerations

When exposing MQTT or Home Assistant to the internet:

⚠️ NEVER expose port 1883 directly to the internet
⚠️ Use strong passwords (not mqttpassword!)
⚠️ Consider using VPN (Tailscale/WireGuard) for remote access
⚠️ Enable Home Assistant’s built-in 2FA
⚠️ Regularly update both Solar Assistant and Home Assistant

🎉 Conclusion

Congratulations! You’ve successfully connected Solar Assistant to Home Assistant using MQTT. Now you have:

✅ Live solar data in your Home Assistant dashboard
✅ Beautiful power flow visualization
✅ Automated control of appliances based on solar availability
✅ Energy tracking and statistics
✅ Foundation for unlimited automations

Your solar system is now truly smart! 🚀