Energy is related to Fuel. Fuel is related to Natural. Natural is a type of Cast. 
Fire is related to Steam. Steam is related to Pot. Pot is a different concept from Want. Want is a synonym of Lack. 
Energy <--RelatedTo--> Fuel <--RelatedTo--> Natural --IsA--> Cast 
Fire <--RelatedTo--> Steam <--RelatedTo--> Pot <--DistinctFrom--> Want <--Synonym--> Lack 