I am using the following terms thus: essence refers to who God is ..., and nature to what God is like. When we think of the divine attributes, we are working with this latter category. This very roughly corresponds to the Eastern distinction between essence and energies or powers. (Robert Letham, Systematic Theology, 157)
While not being an expert on how Eastern Orthodoxy exactly uses the term "energy" as opposed to "essence," I somehow doubt that Letham is correct in his understanding of what "energies" are. Do "energies" really correlate with the nature of God? Since in Eastern Orthodoxy, the focus is on theosis which is a union with the "energies" of God, a correlation of "energies" with "nature" seem to imply that Man actually become like God by nature, so we come to have a divine nature? What does that even mean?