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Tag: weatherflow

  • Adding Weather Forecast to the Predbat Table Card in Home Assistant

    Predbat is brilliant at building smart charging and discharging plans for my home battery system, based on real-time energy costs, predicted house load, and solar forecasts. It uses Solcast data to predict generation and works out the best times to import, export, or hold energy.

    predbat table card weather columns

    But while Solcast takes weather into account when generating its solar forecast, I often found myself wondering why a particular slot was being scheduled a certain way. Was it cloudy? Raining? Very hot? All of these could affect either solar production or battery efficiency.

    That’s when I decided to bring weather information directly into the Predbat Table Card.

    Why Add Weather to the Table?

    Although Predbat itself does not use the weather entity directly, it’s still useful to overlay forecast conditions with the battery plan. This extra context helps me better understand why certain slots are heavy on import or export, especially when the solar forecast looks optimistic but the weather conditions are less than ideal.

    By seeing temperature, cloud cover, or rain in each 30-minute slot, I can cross-reference the charging plan with real-world weather, and make sense of some edge-case decisions.

    How the Integration Works

    The Predbat Table Card supports optional weather and temperature columns through two features I added:

    • weather-column: shows a weather icon for the slot
    • temp-column: shows the predicted temperature
    • rain-column: shows the predicted chance of rain

    To enable them, you need a valid forecast-capable weather entity in Home Assistant and to define it using weather_entity.

    Example Configuration

    Here’s how I set it up in my YAML:

    type: custom:predbat-table-card
title: Predbat Plan with Weather
weather_entity: weather.forecast_home
columns:
  - time-column
  - weather-column
  - temp-column
    - rain-column
  - import-column
  - state-column

    You can of course rearrange or add more columns like export-column, load-column, or soc-column etc as needed.

    Notes on Forecast Compatibility

    This feature only works with forecast-style weather entities that follow the Home Assistant spec. Tested working examples include:

    • weather.met_home (from Met.no)
    • weather.weatherflow_forecast (from the WeatherFlow integration)
    • weather.met_office_yourlocation (from the Met Office weather integration)

    If the weather forecast does not cover the full duration of the Predbat plan (e.g. forecast ends before the plan does), then no weather icon or temperature will show for those slots.

    Colour-Coding and Hover Details

    To quickly spot critical conditions, the table applies colour coding:

    • Red: temperature over 25°C – which could reduce solar panel efficiency
    • Blue: temperature below 0°C – which could reduce battery efficiency

    Each icon also supports mouse-over tooltips, where you can view the detailed weather condition and temperature value.

    If you want to try this yourself, grab the latest version of Predbat Table Card and follow the weather column documentation.

  • Using WeatherFlow Tempest to Warm My Tesla for the School Run

    As a parent juggling the school run every morning, there’s one thing I really don’t enjoy – scraping ice off the car while trying to wrangle two teenagers and get out the door on time. So I’ve automated the process of pre-heating and defrosting my Tesla using my WeatherFlow Tempest weather station and Home Assistant.

    Tesla being heated

    WeatherFlow Tempest is a smart weather station that gives me highly accurate outdoor temperature data from my own garden. More accurate, in fact, than the Tesla’s own temperature sensors when the car is asleep.

    I use the Tessie integration in Home Assistant to communicate with my car. It allows me to send commands like “turn on climate control” even when the Tesla is sleeping, without the delay or failure that sometimes occurs with the native Tesla integration.

    Why Use Tempest Instead of Tesla’s Own Temperature Reading?

    Tesla goes into a deep sleep mode overnight to conserve energy. That’s great for battery life, but not so great if you want reliable temperature data in the early morning. The external temperature reported by the car can be outdated or missing altogether until the car is awake and responsive.

    Instead, I rely on my WeatherFlow Tempest’s temperature sensor, which continues to report accurate live data overnight.

    The Automation Setup

    Every weekday morning at exactly 8.00am, my Home Assistant instance checks the current outside temperature reported by the Tempest. If it’s below 3°C, the automation triggers Tessie to enable climate control in the car for 15 minutes – enough to warm the cabin and defrost the windows. I also make sure I only set this on school days.

    I also receive a notification letting me know that the defrost has been enabled.

    Here’s the automation in full:

    alias: Warm Car Automation
description: At 08.00 every school day check outside temp and defrost if below 3C
mode: single
triggers:
  - at: "08:00:00"
    platform: time
conditions:
  - condition: time
    weekday:
      - mon
      - tue
      - wed
      - thu
      - fri
  - condition: numeric_state
    entity_id: sensor.tempest_temperature
    below: 3
actions:
  - service: climate.turn_on
    target:
      entity_id: climate.none_climate
  - service: notify.notify
    data:
      message: "Car Defrost Enabled for 15 mins"
  - service: notify.persistent_notification
    data:
      title: "Car Defrost Enabled"
      message: "Car Defrost Enabled for 15 mins"

    You can take this further by:

    • Tracking how often the automation is triggered using a counter or helper.
    • Adding a secondary check for battery level to avoid defrosting if your range is low.
    • Turning the climate off again after a set duration (or allowing Tesla’s own timeout to do it for you).

    This small quality-of-life improvement saves me time and hassle every winter morning, and it’s yet another example of how Home Assistant can bring together multiple smart devices into a seamless routine.