A good poem generates energy, or better yet, is energy.  What does this mean?  That there’s action and contrast.  Movement.  Transformation.  To better understand, ponder the opposite:  stasis, inertia.  Passivity and monotony.

To make an image or idea dynamic means to give it something to spark against, to put it into contact with something else.  You could try banging a flint against empty space, but nothing will come of it.  Take a poem you love and examine how the sparks are created.  Do the images and ideas interact, bang into each other like excited atoms, or are they suspended in a sterile environment, cool and aloof?

I try to keep thinking about energy not only during the writing process but also (and perhaps especially) during revision.  Having images and ideas already on paper to work with – to rearrange, expand upon, cut, simplify, complicate, connect – makes the job of activation easier.