Yes, DOE is a Scrabble word!

Letter values in Scrabble US: D 2, O 1, E 1.

Is it a valid word?

DOE is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

the federal department responsible for maintaining a national energy policy of the United States; created in 1977
mature female of mammals of which the male is called `buck'

Also: department of energy, energy department.