EPEX Spot Sensor

This component is an addition to the EPEX Spot integration.

EPEX Spot Sensor add one or more binary sensors which can be configured to turn on at the cheapest or most expensive time interval of the day. The length of the time interval can be configured, as well as whether the interval shall be used contiguously or intermittently.

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Installation

1. Ensure that HACS is installed.

2. Open HACS, then select Integrations.

3. Select ⋮ and then Custom repositories.

4. Set Repository to https://github.com/mampfes/ha_epex_spot_sensor
   and Category to Integration.

5. Install EPEX Spot Sensor integration via HACS:

   

   If the button doesn't work: Open HACS > Integrations > Explore & Download Repositories and select integration EPEX Spot Sensor.

6. Add helper(s) provided by EPEX Spot Sensor to Home Assistant:

   

   If the button doesn't work: Open Settings > Devices & services > Helpers > Create Helper and select EPEX Spot Sensor.

In case you would like to install manually:

1. Copy the folder custom_components/epex_spot_sensor to custom_components in your Home Assistant config folder.

2. Add helper(s) provided by EPEX Spot Sensor to Home Assistant:

   

   If the button doesn't work: Open Settings > Devices & services > Helpers > Create Helper and select EPEX Spot Sensor.

Configuration Options

1. Earliest Start Time
   Earliest time to start the appliance.

2. Latest End Time
   Latest time to end the appliance. Set it to same value as earliest start time to cover 24h. If set to smaller value than earliest start time, it automatically refers to following day.

3. Duration
   Required duration to complete the appliance. In Exact mode, this is the exact duration. In Flexible mode, this becomes the maximum duration.

4. Remaining Duration Entity
   Optional entity which indicates the remaining duration. If entity is set, it replaces the static duration and overrides flexible duration mode. If the state of the Remaining Duration Entity changes between Earliest Start Time and Latest End Time, the configured Earliest Start Time will be ignore and the latest change time of the Remaining Duration Entity will the used instead.

5. Duration Mode
   Selects whether the duration is Exact (default) or Flexible:

   • Exact: Find intervals of exactly the specified duration
   • Flexible: Find intervals between minimum and maximum duration, stopping when prices exceed the threshold

6. Minimum Duration
   (Flexible mode only) The minimum required duration. Only appears when Duration Mode is set to Flexible. Must be less than or equal to the configured duration (maximum).

7. Price Tolerance (%)
   Allow time slots within ±X% of the cheapest/most expensive price. Default is 0% (exact matching). Higher values provide more flexibility in scheduling while staying close to optimal prices.

   • 0% = Exact cheapest/most expensive (default behavior)
   • 10-20% = Moderate flexibility, good for most use cases
   • 50%+ = High flexibility, prioritizes convenience over cost optimization

   When multiple intervals are within tolerance, the system prefers earlier start times.

8. Price Mode
   Selects whether the sensor shall react on the cheapest or the most expensive prices between Earliest Start Time and Latest End Time.

9. Interval Mode
   Selects whether the specified duration shall be completed in a single, contiguous interval or can be split into multiple, not contiguous intervals (intermittend).

Sensor Attributes

1. Earliest Start Time
   Reflects the configured Earliest Start Time.

2. Latest End Time
   Reflects the configured Latest End Time.

3. Duration
   Reflects the used value for duration. In Exact mode, this is the configured duration (or Remaining Duration Entity state). In Flexible mode, this represents the maximum duration.

4. Remaining Duration Entity
   Optional entity which indicates the remaining duration. If entity is set, it replaces the static duration and overrides flexible duration mode.

5. Duration Mode
   Reflects the configured Duration Mode (Exact or Flexible). In Flexible mode, the system finds intervals between minimum and maximum duration that stay within the price threshold.

6. Minimum Duration
   (Flexible mode only) The minimum required duration. Only present when Duration Mode is set to Flexible.

7. Price Tolerance
   Reflects the configured Price Tolerance percentage (0-100%). Shows how much price flexibility is allowed when selecting time slots.

8. Interval Start Time Reflects the actual start time of the interval, which is either the configured Earliest Start Time or the latest change time of the Remaining Duration Entity if the state of the entity changed between Earliest Start Time and Latest End Time.

9. Price Mode
   Reflects the configured Price Mode.

10. Interval Mode
    Reflects the configured Interval Mode.

11. Enabled
    Set to true if current time is between Earliest Start Time and Latest End Time.

12. Data
    List of calculated intervals to switch sensor on, consisting of start_time, end_time and rank (for Interval Mode intermittend only).

UI Visualization (historic + selected intervals)

Each binary sensor now exposes an additional attribute visualization_data that is designed for dashboards. It contains:

• market_prices: historic/forecast price buckets (start_time, end_time, price)
• selected_intervals: the intervals chosen by the sensor logic
• price_range: min/max values for quick chart scaling
• price_unit, window_start, window_end

You can use this attribute with custom Lovelace cards (for example [apexcharts-card]) to overlay selected runtime intervals on top of the hourly prices.

Example template sensor to flatten data for charts:

template:
  - sensor:
      - name: "Waschmaschine Price Points"
        state: "{{ now() }}"
        attributes:
          points: >-
            {{ state_attr('binary_sensor.waschmaschine', 'visualization_data').market_prices
               if state_attr('binary_sensor.waschmaschine', 'visualization_data') else [] }}
          selected: >-
            {{ state_attr('binary_sensor.waschmaschine', 'visualization_data').selected_intervals
               if state_attr('binary_sensor.waschmaschine', 'visualization_data') else [] }}