Calculating cost

Cost Rate

With helpers, you can calculate a rough estimate of the 'cost rate': The rate in euro per hour at the current energy price and Sessy power.

• Get the energy price in €/kWh
• Get Sessy power
• Calculate the depreciation per Wh: purchase cost divided by 6000 cycles of 6 kWh charging and 5 kWh discharging (in this example: € 0,04 depreciation per kWh charged AND discharged)
• Multiply the depreciation rate with the current power to get the current depreciation rate
• Multiply the current energy price with the current power to get the current energy cost rate

{% set energy_price = states("sensor.energy_price") | float *-1 %}
{% set sessy_power = states("sensor.sessy_dxxx_power") | int / 1000 %}
{% set sessy_depreciation_rate = 2750 / (6000 * ( 6 + 5 )) %}{# depreciation per kWh #}
{% set energy_cost_rate = sessy_power * energy_price %}
{% set depreciation_cost_rate = sessy_power | abs * sessy_depreciation_rate %}

{{ energy_cost_rate + depreciation_cost_rate }}

Unit of measurement	€/h
State class	measurement

Cost sensor

To aggregate the cost per day, add a Riemann Sum helper:

Display statistics

View the generated statistics for the just created cost sensor with statistics-graph cards:

chart_type: bar
title: Sessy Cost
period: day
type: statistics-graph
entities:
  - sensor.sessy_dxxx_cost
stat_types:
  - change
days_to_show: 30