EPEX Spot

This component adds electricity prices from stock exchange EPEX Spot to Home Assistant. EPEX Spot does not provide free access to the data, so this component uses different ways to retrieve the data.

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There is a companion integration which simplifies the use of EPEX Spot integration to switch on/off an application depending on the energy market prices:

https://github.com/mampfes/ha_epex_spot_sensor

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You can choose between multiple sources:

1. Awattar Awattar provides a free of charge service for their customers. Market price data is available for Germany and Austria. So far no user identifiation is required.

2. EPEX Spot Web Scraper This source uses web scraping technologies to retrieve publicly available data from its website.

3. SMARD.de SMARD.de provides a free of charge API to retrieve a lot of information about electricity market including market prices. SMARD.de is serviced by the Bundesnetzagentur, Germany.

4. smartENERGY.at smartENERGY.at provides a free of charge service for their customers. Market price data is available for Austria. So far no user identifiation is required.

5. Energyforecast.de Energyforecast.de provides services to get market price data forecasts for Germany up to 96 hours into the future. An API token is required.

If you like this component, please give it a star on github.

Installation

1. Ensure that HACS is installed.

2. Install EPEX Spot integration via HACS:

   

3. Add EPEX Spot integration to Home Assistant:

   

In case you would like to install manually:

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

2. Add EPEX Spot integration to Home Assistant:

   

Sensors

This integration provides the following sensors:

1. Net market price
2. Market price
3. Average market price during the day
4. Median market price during the day
5. Lowest market price during the day
6. Highest market price during the day
7. Current market price quantile during the day
8. Rank of the current market price during the day

The EPEX Spot Web Scraper provides some additional sensors:

• Buy Volume
• Sell Volume
• Volume

NOTE: For GB data, the prices will be shown in GBP instead of EUR. The sensor attribute names are adjusted accordingly.

1. Net Market Price Sensor

The sensor value reports the net market price in €/£/kWh. The price value will be updated every hour to reflect the current net market price.

The sensor attributes contains a list of all available net market prices (for today and tomorrow if available) in €/£/kWh.

data:
  - start_time: "2022-12-15T23:00:00+00:00"
    end_time: "2022-12-16T00:00:00+00:00"
    price_per_kwh: 0.12485
  - start_time: "2022-12-16T00:00:00+00:00"
    end_time: "2022-12-16T01:00:00+00:00"
    price_per_kwh: 0.12235
  - start_time: "2022-12-16T01:00:00+00:00"
    end_time: "2022-12-16T02:00:00+00:00"
    price_per_kwh: 0.12247

The net market price will be calculated as follows: <Net Price> = <Market Price> + <Surcharges> + <Tax>

• Net market price is the price you have to pay at the end, including taxes, surcharges and VAT.
• Market price is the energy price from EPEX Spot excluding taxes, surcharges, VAT.
• 2 different types of surcharges can be adjusted:
  1. Percentage Surcharge, stated in % of the EPEX Spot market price.
  2. Absolute Surcharge, stated in €/£/kWh, excluding VAT.
• Tax, e.g. VAT

The values for surcharges and tax can be adjusted in the integration configuration.

Example:

Percentage Surchage = 3%
Absolute Surcharge = 0.012 €/£/kWh
Tax = 19%

Net Price = ((Market Price * 1.03) + 0.012) * 1.19

Note about smartENERGY.at

As of Feb 2024, even though smartENERGY says that the prices reported by the API already include 20% tax (meaning users would configure the sensor to add a static €0.0144 to every price value from the API), this is incorrect, and the API reports pricing without Tax.

To get the actual, current Net Price listed by smartENERGY on their website, configure:

• Absolute surcharge = €0.012
• Tax = 20%

2. Market Price Sensor

The sensor value reports the EPEX Spot market price in €/£/kWh. The market price doesn't include taxes, surcharges, VAT. The price value will be updated every hour to reflect the current market price.

The sensor attributes contains additional values:

• The market price in €/£/kWh.
• A list of all available market prices (for today and tomorrow if available) in €/£/kWh.

price_per_kwh: 0.089958
data:
  - start_time: "2022-12-15T23:00:00+00:00"
    end_time: "2022-12-16T00:00:00+00:00"
    price_per_kwh: 0.092042
  - start_time: "2022-12-16T00:00:00+00:00"
    end_time: "2022-12-16T01:00:00+00:00"
    price_per_kwh: 0.090058
  - start_time: "2022-12-16T01:00:00+00:00"
    end_time: "2022-12-16T02:00:00+00:00"
    price_per_kwh: 0.126067

3. Average Market Price Sensor

The sensor value reports the average EPEX Spot market price during the day. The sensor value reports the market price in €/£/kWh.

4. Median Market Price Sensor

The sensor value reports the median EPEX Spot market price during the day. The sensor value reports the market price in €/£/kWh.

5. Lowest Market Price Sensor

The sensor value reports the lowest EPEX Spot market price during the day. The sensor value reports the market price in €/£/kWh. The market price in €/£/kWh is available as sensor attribute.

The sensor attributes contains the start and endtime of the lowest market price timeframe.

price_per_kwh: 0.09
start_time: "2023-02-15T22:00:00+00:00"
end_time: "2023-02-15T23:00:00+00:00"

6. Highest Market Price Sensor

The sensor value reports the highest EPEX Spot market price during the day. The sensor value reports the market price in €/£/kWh. The market price in €/£/kWh is available as sensor attribute.

The sensor attributes contains the start and endtime of the highest market price timeframe.

price_per_kwh: 0.33
start_time: "2023-02-15T22:00:00+00:00"
end_time: "2023-02-15T23:00:00+00:00"

7. Quantile Sensor

The sensor value reports the quantile between the lowest market price and the highest market price during the day in the range between 0 & 1.

Examples:

• The sensor reports 0 if the current market price is the lowest during the day.
• The sensor reports 1 if the current market price is the highest during the day.
• If the sensor reports e.g., 0.25, then the current market price is 25% of the range between the lowest and the highest market price.

8. Rank Sensor

The sensor value reports the rank of the current market price during the day. Or in other words: The number of hours in which the price is lower than the current price.

Examples:

• The sensor reports 0 if the current market price is the lowest during the day. There is no lower market price during the day.
• The sensor reports 23 if the current market price is the highest during the day (if the market price will be updated hourly). There are 23 hours which are cheaper than the current hour market price.
• The sensor reports 1 if the current market price is the 2nd cheapest during the day. There is 1 one which is cheaper than the current hour market price.

Service Calls

List of Service Calls:

• Get Lowest Price Interval
• Get Highest Price Interval
• Fetch Data

1. Get Lowest and Highest Price Interval

Requires Release >= 2.0.0

Get the time interval during which the price is at its lowest/highest point.

Knowing the hours with the lowest / highest consecutive prices during the day could be an interesting use case. This might be of value when looking for the most optimum time to start your washing machine, dishwasher, dryer, etc.

With this service call, you can let the integration calculate the optimal start time. The only mandatory attribute is the duration of your appliance. Optionally you can limit start- and end-time, e.g. to start your appliance only during night hours.

epex_spot.get_lowest_price_interval
epex_spot.get_highest_price_interval

Service data attribute	Optional	Description	Example
device_id	yes	A EPEX Spot service instance ID. In case you have multiple EPEX Spot instances.	9d44d8ce9b19e0863cf574c2763749ac
earliest_start	yes	Earliest time to start the appliance.	"14:00:00"
earliest_start_post	yes	Postponement of earliest_start in days: 0 = today (default), 1= tomorrow	0
latest_end	yes	Latest time to end the appliance.	"16:00:00"
latest_end_post	yes	Postponement of latest_end in days: 0 = today (default), 1= tomorrow	0
duration	no	Required duration to complete appliance.	See below...

Notes:

• If earliest_start is omitted, the current time is used instead.
• If latest_end is omitted, the end of all available market data is used.
• earliest_start refers to today if earliest_start_post is omitted or set to 0.
• latest_end will be automatically trimmed to the available market area.
• If earliest_start and latest_end are present and latest_end is earlier than (or equal to) earliest_start, then latest_end refers to tomorrow.
• device_id is only required if have have setup multiple EPEX Spot instances. The easiest way to get the unique device id, is to use the Developer Tools -> Services.

Service Call Examples:

service: epex_spot.get_lowest_price_interval
data:
  device_id: 9d44d8ce9b19e0863cf574c2763749ac
  earliest_start: "14:00:00"
  latest_end: "16:00:00"
  duration:
    hours: 1
    minutes: 0
    seconds: 0

service: epex_spot.get_lowest_price_interval
data:
  earliest_start: "14:00:00"
  latest_end: "16:00:00"
  duration: "00:30:00" # 30 minutes

service: epex_spot.get_lowest_price_interval
data:
  duration: "00:30" # 30 minutes

service: epex_spot.get_lowest_price_interval
data:
  duration: 120 # in seconds -> 2 minutes

# get the lowest price all day tomorrow:
service: epex_spot.get_lowest_price_interval
data:
  earliest_start: "00:00:00"
  earliest_start_post: 1
  latest_end: "00:00:00"
  latest_end_post: 2
  duration: "01:30:00" # 1h, 30 minutes

Response

The response contains the calculated start and end-time and the average price per kWh.

Example:

start: "2024-11-04T23:00:00+01:00"
end: "2024-11-05T00:00:00+01:00"
price_per_kwh: 0.098192
net_price_per_kwh: 0.13223

With Home Assistant release >= 2023.9 you can use the Template Integration to create a sensor (in your configuration.yaml file) that shows the start time:

template:
  - trigger:
      - platform: time
        at: "00:00:00"
    action:
      - service: epex_spot.get_lowest_price_interval
        data:
          earliest_start: "20:00:00"
          latest_end: "23:00:00"
          duration:
            hours: 1
            minutes: 5
        response_variable: resp
    sensor:
      - name: Start Appliance
        device_class: timestamp
        state: "{{ resp.start is defined and resp.start }}"

This sensor can be used to trigger automations:

trigger:
  - platform: time
    at: sensor.start_appliance
condition: []
action: []

2. Fetch Data

Requires Release >= 2.1.0

Fetch data from all services or a specific service.

epex_spot.fetch_data

Service data attribute	Optional	Description	Example
device_id	yes	A EPEX Spot service instance ID. In case you have multiple EPEX Spot instances.	9d44d8ce9b19e0863cf574c2763749ac

3. The EPEX Spot Sensor Integration

A significantly easier, GUI-based method to achieve some of the results listed above is to install the EPEX Spot Sensor integration (via HACS) and configure helpers with it. An example for this method is covered in FAQ 2 below.

FAQ

1. How can I show a chart of the next hours?

With ApexCharts, you can easily show a chart like this to see the hourly net prices for today:

You just have to install ApexCharts (via HACS) and enter the following data in the card configuration:

type: custom:apexcharts-card
header:
  show: true
  title: Electricity Prices
graph_span: 48h
span:
  start: day
now:
  show: true
  label: Now
series:
  - entity: sensor.epex_spot_data_net_price
    name: Electricity Price
    type: column
    extend_to: end
    data_generator: |
      return entity.attributes.data.map((entry) => {
        return [new Date(entry.start_time), entry.price_per_kwh];
      });

See this Show & Tell post for a fancier, more elaborate version of this card that can auto-hide the next day's prices when they aren't available, colour the hourly bars depending on the price, etc.

Assumptions:

This example assumes that you are using smartENERGY.at as a source and want to display the Net Price in €/kWh for the next 48 hours. The value for entity and the entry being processed by the data_generator are specific to this data source:

If you are using a different source, you will need to first update sensor.epex_spot_data_net_price to use the correct sensor for your configuration (check which Entities you have available under Devices → Integrations → EPEX Spot → # Entities) and then change entry.price_per_kwh to the attribute that you want to use from your sensor of choice. If your data source does not report prices for the next day, you can change the graph_span to 24h to get rid of the empty space that this configuration would create.

2. How can I optimise the best moment to start appliances?

It might be an interesting use case to know what the hours with lowest consecutive prices during the day are. This might be of value when looking for the most optimum time to start your washing machine, dishwasher, dryer, etc. The most convenient way to do this would be to install and configure the EPEX Spot Sensor (via HACS).

Example

• Your dishwasher cycle takes 3 hours and 15 minutes to run
• You want to run a full, continuous cycle in the time-window when power is the cheapest for those 3 hours & 15 minutes
• You don't care at what exact time the dishwasher cycle starts or finishes

Create & Configure a Helper

Create a Helper by going to Settings → Devices & Services → Helpers → Create Helper → EPEX Spot Sensor and configure it like so:

This creates a binary sensor binary_sensor.dishwasher_cheapest_window with the Friendly Name "Dishwasher: Cheapest Window". The sensor turns on at the start of the cheapest time-window, off at the end of the time-window, and reports the start_time & end_time for this time-window in its attributes.

Depending on your implementation use-case, there are two ways to proceed:

Case 1: Automating the dishwasher If the dishwasher can be controlled via Home Assistant, or you can use some kind of smart-device to start the dishwasher cycle, you could create an automations that triggers when binary_sensor.dishwasher_cheapest_window turns on.

Case 2: Manually starting / scheduling the dishwasher If your dishwasher cannot be automated, you can create a card on your dashboard that tells you either what time, or in how much time you should should manually start your dishwasher or schedule it to start.

What time should I start the dishwasher? Create a Template Sensor by going to Settings → Devices & Services → Helpers → Create Helper → Template → Template a sensor. Give it a Friendly name, for example "Next Dishwasher Start (Time)" and under "State Template", enter

{% set data = state_attr('binary_sensor.dishwasher_cheapest_window', 'data') %}
{% set now = now() %}
{% set future_windows = data | selectattr('start_time', '>', now.timestamp() | timestamp_local) | list %}
{% if future_windows %}
  {% set next_window = future_windows | first %}
  {% set start_time = strptime(next_window['start_time'], '%Y-%m-%dT%H:%M:%S%z') %}
  {{ start_time.strftime('%H:%M on %d/%m/%y') }}
{% else %}
  Waiting for new data
{% endif %}

This Template Sensors uses the data from the attributes of the "Dishwasher: Cheapest Window" binary sensor created earlier with the EPEX Spot Sensor integration, checks whether the start_time is in the future, and displays the start_time as H:M on d/m/y.

In how much time from now should I start the dishwasher? Create a Template Sensor by going to Settings → Devices & Services → Helpers → Create Helper → Template → Template a sensor. Give it a Friendly name, for example "Next Dishwasher Start (Duration)" and under "State Template", enter

{% set data = state_attr('binary_sensor.dishwasher_cheapest_window', 'data') %}
{% set now = now() %}
{% set future_windows = data | selectattr('start_time', '>', now.timestamp() | timestamp_local) | list %}
{% if future_windows %}
  {% set next_window = future_windows | first %}
  {% set start_time = strptime(next_window['start_time'], '%Y-%m-%dT%H:%M:%S%z') %}
  {% set time_to_start = (start_time - now).total_seconds() %}
  {% set hours = (time_to_start // 3600) | int %}
  {% set minutes = ((time_to_start % 3600) // 60) | int %}
  {% set time_str = '{:02}:{:02}'.format(hours, minutes) %}
  {{ time_str }}
{% else %}
  Waiting for new data
{% endif %}

In addition to what the previous sensor does, this one calculates how long it is from now till the start_time, and displays the result in H:M.

In both cases, if the start_time has already passed, the sensors display Waiting for new data.

Finally, create Entity Cards on your dashboard with the sensors you want to display.

See this Show & Tell post for a fancier, more elaborate version of this card that can show several appliances at once, auto hide ones that don't have data, and even hide itself when there is no data at all.

3. I want to combine and view everything

Here's another ApexCharts example. It shows the price for the current day, the next day and the min/max value for each day. Furthermore, it also fills the hours during which prices are lowest (see 2.)

type: custom:apexcharts-card
header:
  show: false
graph_span: 48h
span:
  start: day
now:
  show: true
  label: Now
color_list:
  - var(--primary-color)
series:
  - entity: sensor.epex_spot_data_price
    yaxis_id: uurprijs
    float_precision: 2
    type: line
    curve: stepline
    extend_to: false
    show:
      extremas: true
    data_generator: >
      return entity.attributes.data.map((entry, index) => { return [new
      Date(entry.start_time).getTime(), entry.price_per_kwh]; }).slice(0,24);
    color_threshold:
      - value: 0
        color: "#186ddc"
      - value: 0.155
        color: "#04822e"
      - value: 0.2
        color: "#12A141"
      - value: 0.25
        color: "#79B92C"
      - value: 0.3
        color: "#C4D81D"
      - value: 0.35
        color: "#F3DC0C"
      - value: 0.4
        color: red
      - value: 0.5
        color: magenta
  - entity: sensor.epex_spot_data_price
    yaxis_id: uurprijs
    float_precision: 2
    type: line
    curve: stepline
    extend_to: end
    show:
      extremas: true
    data_generator: >
      return entity.attributes.data.map((entry, index) => { return [new
      Date(entry.start_time).getTime(), entry.price_per_kwh]; }).slice(23,47);
    color_threshold:
      - value: 0
        color: "#186ddc"
      - value: 0.155
        color: "#04822e"
      - value: 0.2
        color: "#12A141"
      - value: 0.25
        color: "#79B92C"
      - value: 0.3
        color: "#C4D81D"
      - value: 0.35
        color: "#F3DC0C"
      - value: 0.4
        color: red
      - value: 0.5
        color: magenta
  - entity: sensor.epex_spot_data_price
    yaxis_id: uurprijs
    type: area
    color: green
    float_precision: 2
    curve: stepline
    extend_to: false
    data_generator: >
      return entity.attributes.data.map((entry, index) => { return [new
      Date(entry.start_time).getTime(), entry.price_per_kwh];}).slice(parseInt(hass.states['sensor.epex_start_low_period'].state.substring(0,2)),parseInt(hass.states['sensor.epex_start_low_period'].state.substring(0,2))+4);

experimental:
  color_threshold: true
yaxis:
  - id: uurprijs
    decimals: 2
    apex_config:
      title:
        text: €/kWh
      tickAmount: 4
apex_config:
  legend:
    show: false
  tooltip:
    x:
      show: true
      format: HH:00 - HH:59

Assumptions:

This example assumes that you are using the EPEX Spot Web Scraper as a source and want to display the Price in €/kWh for the next 48 hours, and highlight a 4-hour block where the electricity price is the lowest. As with the previous example, the entity and the entry being processed by the data_generator are specific to this data source, and you should update them to match your configuration.

In case the electricity pricing in your market results in the entire sparkline having one static colour (for example, the line always appears magenta), you will need to fine-tune the color_threshold entries . You can do this by either editing the value entries in the example above, or you can also add more value and color pairs if you want additional colours.

To change the colour of the highlighted cheapest time-period, update the color entry under type: area, and to change the length of the time-period, change the +4 at the end of the data_generator.