The Holy Spirit is the third person of the Trinity. The Scriptures teach us that God is a Trinity—He is three persons, but one God. I explained this concept in detail, and how the doctrine is reflected in Genesis, in the first chapter of my book, No Time for Itching Ears.
There are a number of verses that tell us about the work of the Holy Spirit in creation. In Genesis 1:2, we have the first mention of the Spirit.
And the Spirit of God was hovering over the face of the waters.
It is possible that I might be reading too much into this, but in a universe that God had just created, by the authority of the Father, and through the work and word of the Son, it was necessary for there to be an input of energy. God provided this by the work of His Spirit. Therefore, the “hovering” can be seen as a movement, and therefore an input of energy.
The Hebrew word translated as Spirit here, and throughout the Old Testament, is ruach.
This word is also used for wind or for breath. The context tells us which it should be, though occasionally English translations miss the point of this ambiguity, in my opinion. For example:
By the word of the LORD the heavens were made, And all the host of them by the breath of His mouth. (Psalm 33:6.)
Many people have spotted that this verse mentions the activity of Jesus in creation. After all, Colossians 1 also reminds us that everything was made through, by and for Jesus, and John 1 reminds us that Jesus is the Word of God. But notice the latter half of the verse. The host of heaven—possibly the stars—was made by the “breath of his mouth”. The word for breath in this verse is, as you probably guessed, ruach. Therefore, the host of heaven was made by the Holy Spirit. This is emphasized in Job 26:13: “By His Spirit He adorned the heavens.”
The New Testament is full of this link between the Spirit and power (see 1 Corinthians 2:4). It is helpful for us to remember that it has always been this way. The Holy Spirit was there at creation, because He was there before creation.