Abstract
The plasma energy flux is frequently equated to the kinetic energy flux. However, the periodic exchange between kinetic and potential energy in the gyratory motion produces a spurious contribution, which is balanced by a potential energy flux. The total energy flux is more meaningful. This is equivalent to the guiding-centre energy flux. The convective part of this is (3/2) Gamma T, not (5/2) Gamma T as for the kinetic energy flux.