id	keyword
ajceb-2973	energy
ajceb-2973	cost
ajceb-2973	building
ajceb-2973	operating
ajceb-2973	new
ajceb-2973	construction
ajceb-2973	recurrent
ajceb-2973	services
ajceb-2973	capital
ajceb-2973	journal
ajceb-2973	case
ajceb-2973	economics
ajceb-2973	year