Once again I’ve reached the limits of my understanding of Templating …
I have a couple of utility_meters and would like to show their last_period states in a pie_chart
Extracting the last_period state in a template sensor wors flawless like this:
- platform: template
sensors:
ac_01_month_energy_draw_last:
friendly_name: 'AC01 last month'
unit_of_measurement: 'kWh'
value_template: '{{ states.sensor.ac_01_month_energy_draw.attributes.last_period | float }}'
However, I really want to avoid creating dozens of template sensors…
so I tried this:
entities:
- input_number.total_power_consumption_last_month
type: 'custom:config-template-card'
variables:
- '{{ states.sensor.ac_01_month_energy_draw.attributes.last_period | float }}'
card:
entities:
- entity: '${vars[0]}'
name: AC01
title: Power Consumption Last Month
total_amount: input_number.total_power_consumption_last_month
type: 'custom:pie-chart-card'
unknownText: else
But it doesn’t work 
How do I propperly phrase the variables?