The report variables you show are only used with a buss type that includes storage. The buss types ending with the word Storage will use those report variables.

ElectricLoadCenter:Distribution,

  A6,  \field Electrical Buss Type
   \type choice
   \key AlternatingCurrent
   \key AlternatingCurrentWithStorage
   \key DirectCurrentWithInverter
   \key DirectCurrentWithInverterDCStorage
   \key DirectCurrentWithInverterACStorage
   \default AlternatingCurrent