Both Mike Sigman and Don Miller have vids out describing reeling silk energy that you might want to learn from.
In Systema, a Russian martial art, reeling silk energy is called "the wave" and is used fairly extensively.
I generally describe it using the image of a fishing rod casting a lure. Think of your feet as being the butt end of the rod, the handhold area of the rod as being your waist, the near end of the rod as being your shoulders, the rod tip as being your active hand, and the lure as being the energy you're projecting.
Clearly the power comes from the butt end of the rod, travels through the springy body of the rod, sails through the tip of the rod, and projects out into and beyond your opponent.
Depending on how you manage the handle of the rod, you can cast the lure anywhere you want, with a great deal of power or very gently.
The rod itself can be either very stiff or very springy, depending on the size and weight of the lure you're casting. Power projects through it nonetheless; it just takes a different dynamic if you're casting a large lure rather than a light one.