The amount a channeler can actually channel will always be higher than the actual power they control. This is because their physical and mental capacity to sustain that power is greater than their mind’s mastery to control the direction of the said power.

It is not unheard of to hear someone who cannot control their powers being able to channel vast amounts of power. It is impossible for someone to channel less power than they are able to control. By this we mean the raw output versus a direct one, your body against conscious manipulation. You may choose to channel less power than your actual capacity to control it; that is not what we mean.

Rikan Alexis of the Mitsutani Clan
Excerpt from Sisterly Visions