Understand it's an informal idiomatic expression best used in casual conversation or writing. His enthusiasm for the project was in spades.
Pro Tip 2/3
Connotative Strength
It implies a strong presence or high level of a quality, significantly more than usual. The way she handled the crisis showed her leadership skills were in spades.
Pro Tip 3/3
Emotional Emphasis
Often conveys the speaker's admiration or emphasis on the intensity of a trait or characteristic. He has creativity in spades, always coming up with new ideas.