[BerntR]

BerntR
Energy doesn't get banked (stored ... dollars in an account) ... the downswing converts potential energy to kinetic. Forces across levers create movement.... that's kinetic energy.

Oh really ......

Energy storage is a very essential topic in a lot of mechanical engineering subjects like noise control and vibration damping. Transducer technology is a subject I know pretty well where energy storage is an essensial challenge. In many cases the efforts are about minimizing energy storage. In other cases it's about tuning. Typical efforts to reduce energy storage in mechanical systems is to reduce mass and add mechanical resistance.

Energy storage is often described with a Q-factor that deals with the ratio of reactive (energy-storing) components to resistive (energy-dissipating) components. http://en.wikipedia.org/wiki/Quality_factor

The down swing converts potential energy (related to g) to kinetic energy, that's true. In addition it stores the kinetic energy that is added by the player working the club. Moving mass is one of the essential ingredients. Most of the mass in the clubhead is there to help the player accumulate energy until impact.