The location service is needed to pair your Bluetooth devices, as requested by Google. You may find the information here: https://developer.android.com/about/versions/marshmallow/android-6.0-changes.html#behavior-hardware-id, where they stated that "To access the hardware identifiers of nearby external devices via Bluetooth and Wi-Fi scans, your app must now have the ACCESS_FINE_LOCATION or ACCESS_COARSE_LOCATION permissions:"
Your location information will only be used on two occasions by the app:
- To pair Bluetooth devices
- Determine your local sunrise and sunset time when you use this feature in the automation.