redundant vs excess

redundant is not a noun while excess is a noun.

Word	Noun	Adjective	Verb	Adverb
redundant	No	Yes	No	No
excess	Yes	Yes	No	No

As adjectives, redundant and excess are synonyms defined as:

Other synonyms of redundant include extra, spare, supererogatory, superfluous, supernumerary, surplus.

redundant (noun)	excess (noun)
	excessive indulgence
	immoderation as a consequence of going beyond sufficient or permitted limits
	a quantity much larger than is needed
	the state of being more than full

redundant (adjective)	excess (adjective)
more than is needed, desired, or required	more than is needed, desired, or required
repetition of same and identical sense with different and non-identical words