Energy Consumption

Today brings an important question to the realms of crypto about energy consumption. While from my understanding Ardor is energy efficient being PoS, the documentation does not seem to mention much about it.

Given Biden's recent push for energy efficient solutions, imo I think this point should be more clearly made as it would seem to be an advantage that should be told.

Some people talk about energy/transaction. Not sure if it is possible but is there a number or formula that could represent ardor energy consumption?

Thanks in advance