Articles on: Vehicles

Solar Charging Automation

Solar charging automation allows you to charge your Tesla using excess solar production from your home solar system. This guide covers how to set up solar charging automation with Teslemetry and Home Assistant, including cost-effective alternatives for frequent charge rate adjustments.


Understanding Solar Charging Costs


Why is Solar Charging Expensive Through the Fleet API?


Solar charging automation typically requires frequent adjustments to your vehicle's charge rate to match available solar power. This can mean sending dozens to hundreds of commands per day as solar production fluctuates. Since Tesla charges for every Fleet API command, and Teslemetry passes these costs through via command credits, solar charging can quickly consume your credits.


Example scenario:

  • Adjusting charge amps every 5 minutes for 8 hours of daylight
  • 96 commands per day x 1 credit each = 96 credits
  • Plus wake commands if the vehicle sleeps between adjustments



Frequently Asked Questions


Can I use Teslemetry for excess solar charging?


Yes, but with important cost considerations. For occasional adjustments, this works well. For continuous real-time optimization, the command credits can add up quickly. Consider using Bluetooth alternatives for the actual charge control while using Teslemetry for monitoring and data.


How do I set up charging on solar automation in Home Assistant?


Option 1: Using Teslemetry (Cloud-based)


This approach uses the Fleet API and consumes command credits for each command.


Option 2: Using Bluetooth (Free, Local)


For frequent charge rate adjustments without command costs, use one of these Bluetooth alternatives:



These allow unlimited local control of charging without consuming command credits.


What Bluetooth alternatives are available for solar charging?


ESPHome Tesla BLE


Created by Yasir Ekinci, esphome-tesla-ble enables ESP32 microcontrollers running ESPHome to connect to your Tesla over Bluetooth Low Energy.


Supported charging commands:

  • Turn charging on/off
  • Set charging amps
  • Set charge limit percentage


Requirements:

  • ESP32 device (tested with M5Stack NanoC6)
  • Python 3.10+
  • ESPHome experience


hass-tesla-bluetooth


Maintained by Teslemetry, hass-tesla-bluetooth is a Home Assistant integration for direct Bluetooth communication with Tesla vehicles.


Important limitations:

  • Vehicles support only 3 simultaneous BLE connections
  • Keeps the vehicle awake while connected
  • Cannot be used alongside Tesla Fleet, Tessie, or core Teslemetry integrations


How do I know when charging is complete vs manually stopped?


The Teslemetry charging sensor provides different states:


State

Meaning

completed

Charging finished because the state of charge limit was reached

stopped

Charging was manually stopped before reaching the SOC limit

charging

Vehicle is actively charging

disconnected

No charging cable connected



Tips for Reducing Command Credit Usage


  1. Use Bluetooth for frequent commands - ESPHome Tesla BLE or hass-tesla-bluetooth for charge amp adjustments
  2. Add delays between commands - Every 5-10 minutes may be sufficient
  3. Set minimum change thresholds - Only send a command if the change is significant (e.g., 2+ amps difference)
  4. Use Teslemetry for monitoring - Streaming telemetry is included in your subscription without per-command costs
  5. Check vehicle state before commanding - Avoid sending commands if the vehicle is asleep (wake costs 20 credits)




Updated on: 01/02/2026

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