Power Snatch is often used towards the start of a training program where the focus is on strength and power development as well as lifting specific fitness. Lifters often use this lift to add variety to their programs and to give the knees a break from the deep squatting positions. It is also used more frequently by CrossFitters when multiple reps are required for time. This variation of the snatch is quicker to perform that the full squat lift and doesn’t take as much out of the legs, therefore is more efficient in high rep WODs.
The movement principles are identical to that of the full squat snatch, the only difference is the receiving position in that you aim to catch the bar above a 90 degree knee bend. Therefore, if the movement pattern is the same as the full squat snatch, more effort and power would be required on the same weight for a power snatch because the bar required more upward momentum in order to travel higher.