COP (Coefficient of Performance) calculation

[tomasenskede]

Given the need to monitor the COP value of the heating system to assess its efficiency, this is how I calculate the COP value. If you use a different method, please feel free to share your approach or provide feedback!

{% set flow = states('sensor.flow_sensor_bf1_30041') | float %}
{% set return_temp = states('sensor.return_line_bt3_30008') | float %}
{% set supply_temp = states('sensor.supply_line_bt2_30006') | float %}
{% set power = states('sensor.varmepump_energi') | float %} {# I couldn't find the energy consumption data in the NIBE integration, so I'm using a different sensor to measure energy consumption #}
{% set specific_heat = 4.186 %} {# Specific heat capacity of water in kJ/kg°C #}
{% set density = 1000 %} {# Water density in kg/m³ #}}
{% if flow > 0 and power > 0 %}
  {% set flow_kg_per_sec = (flow * density) / 60000 %} {# Convert liters/min to kg/s #}
  {% set heat_output_kW = flow_kg_per_sec * specific_heat * (supply_temp - return_temp) %}
  {% set cop = heat_output_kW / power %}
  {{ cop | float | round(2) }}
{% else %}
  0 {# Or 'unavailable' if you prefer #}
{% endif %}