Average cheapest electricity price for appliance runtime

[ENWOD]

Hi all,

I hope you don't mind me adding this here as I'm not even sure it's the right location.

I've been trying to create this for a while now but I'm not good at coding - thankfully our AI overlords at Google. I pieced together this template sensor with Gemini: I'm trying to figure our blueprinting this sensor but believe this is very new functionality within Home Assistant and so doesn't seem fully functional but may be useful to anyone else looking for similar functionality:

You should just be able to paste this into a template sensor and potentially amend the two Octopus / Energy provider current and next day event entities:

event.octopus_energy_electricity_current_day_rates
event.octopus_energy_electricity_next_day_rates

You will also need to create an input_number slider and either call it input_number.appliance_run_time_slider or change the reference in the below code.

This will then output how many hours and minutes to the cheapest time period that you have adjusted with the input slider as well as the time and average cost for this period.

{#-
  =================================================================================================
  USER CONFIGURATION
  - Please update the entity IDs with your specific event entities for current and next-day electricity rates.
  - These can be found under Developer Tools -> States and will likely start with 'event.octopus_energy...'.
  =================================================================================================
-#}
{%- set current_day_entity = 'event.octopus_energy_electricity_current_day_rates' -%}
{%- set next_day_entity = 'event.octopus_energy_electricity_next_day_rates' -%}

{%- set run_time_hours = states('input_number.appliance_run_time_slider') | float(0) -%}
{%- set intervals = (run_time_hours * 2) | int -%}

{#
  - This template combines rate data from both the current day and next day event entities
    to provide a complete view of available future rates.
#}
{%- set current_rates = state_attr(current_day_entity, 'rates') if states(current_day_entity) is not none else [] -%}
{%- set next_day_rates = state_attr(next_day_entity, 'rates') if states(next_day_entity) is not none else [] -%}

{# Combine the two lists of rates. Handle cases where one or both may not be available. #}
{%- set all_rates = (current_rates if current_rates is not none else []) + (next_day_rates if next_day_rates is not none else []) -%}


{# Filter out rates that are in the past, keeping only future slots. #}
{# The 'start' attribute is a datetime object, so we compare it with now() which is also a datetime object. #}
{%- set future_rates = all_rates | selectattr('start', 'ge', now()) | list if all_rates -%}


{# Ensure we have enough future rate data to cover the appliance's run time. #}
{%- if future_rates and future_rates | length >= intervals -%}

  {# A namespace is used to create variables that can be updated from within a loop. #}
  {%- set ns = namespace(min_avg_price=9999, best_start_time=none) -%}

  {# Loop through all possible start times. We stop before the end of the list #}
  {# to ensure there's a full runtime window to check. #}
  {%- for i in range(future_rates | length - intervals + 1) -%}

    {# Get the current "window" of rates to check. #}
    {%- set current_window = future_rates[i:i+intervals] -%}
    
    {# Calculate the total and average price for this window. #}
    {%- set total_price_in_window = current_window | sum(attribute='value_inc_vat') -%}
    {%- set avg_price = total_price_in_window / intervals -%}

    {# If this window's average price is the cheapest we've found so far, store it. #}
    {%- if avg_price < ns.min_avg_price -%}
      {%- set ns.min_avg_price = avg_price -%}
      {%- set ns.best_start_time = current_window[0].start -%}
    {%- endif -%}
  {%- endfor -%}
  
  {%- set time_to_start = ns.best_start_time - now() -%}
  {%- set hours_to_start = (time_to_start.total_seconds() / 3600) | int -%}
  {%- set minutes_to_start = ((time_to_start.total_seconds() % 3600) / 60) | round | int -%}

  {# Output the time until the cheapest start, the start time itself, and the average price. #}
  {# (Avg: {{ (ns.min_avg_price) | round(2) }}p) to display 0.16p for example, or (Avg: {{ (ns.min_avg_price * 100) | round(2) }}p) to display 16.00p #}
{{ hours_to_start }}h {{ minutes_to_start }}m at {{ ns.best_start_time.strftime('%H:%M / %d-%m-%Y') }} (Avg: {{ (ns.min_avg_price * 100) | round(2) }}p)

{%- else -%}
  {# If there's not enough data, output an error message. #}
  Not enough data available
{%- endif -%}

Image showing how this works on the dashboard:

[BottlecapDave]

Hello. This would probably be best within the HA forums or the OE discussions, as this template doesn't seem to ultise this integration at all.

I'd also highlight though that this integration does this already, while automatically adjusting and supporting automations to trigger when within the cheap period. The created sensors produce average 'value' (which are rates when using the OE template) and state the start/end time for the discovered period. Therefore you can just use this integration and then use a template to output the attributes of the created sensor.

[ENWOD]

Thank you and sorry - I was completely unaware of the existing functionality withing this integration too. I think I may have to do a little reading and educate myself a bit more. Really appreciate you commenting and for putting a lot of work into these integrations.