Rene,
You don't need all that, this should be sufficient:
select_capabilities: power_sensor: attributes: value: trueor the equivalent, using an array of attribute names (my favorite):
select_capabilities: power_sensor: attributes: [ 'value' ]or using the other YAML array syntax:
select_capabilities: power_sensor: attributes: - valueYou can also use a negative to suppress an attribute:
select_capabilities: power_sensor: attributes: [ '-units' ]Also, can I ask that you go back and fix the formatting of the code sections of your posts, for the benefit of future readers looking at your question and example solution?