###### Substract DC Input Power from DC Input Power 1 to get both channels #####
###dc_input_power is channel 1+2
###dc_input_power1 is channel 1

- platform: template
  sensors:
    dc_input_power2:
      value_template: >
        {{ (states('sensor.ep500p_dc_input_power') | float - 
        states('sensor.ep500p_dc_input_power1') | float ) | round(0) }}
      unit_of_measurement: 'W'
      friendly_name: DC Input Power 2
      icon_template: mdi:flash

###### Input vs. output power #####

- platform: template
  sensors:
    input_vs_output_power:
      value_template: >
        {{ ((states('sensor.ep500p_dc_input_power') | float +
        states('sensor.ep500p_ac_input_power') | float)      -
        (states('sensor.ep500p_dc_output_power') | float     +
        states('sensor.ep500p_ac_output_power') | float)) | round(0) }}
      unit_of_measurement: 'W'
      friendly_name: Input Output Billanz
      icon_template: mdi:gauge