Can the instantaneous power output of an ac source ever be negative ? Can the average power output be negative ?

Explanation

In LCR circuit, If applied emf is
`epsilon = epsilon_(0) sin omega`t, then the current in the circuit is
I = `I_(0) sin (omega pm phi)`
Instantaneous power output is given by
P = `epsilon I = (epsilon_(0) sin omega t) (I_(0) sin (omega t pm phi )) `
The multiplication of the two functions sin `omega`t and sin `(omega pm phi) ` can be positive or negative as there is a phase difference `phi` between them .
Thus, we can say that the instantaneous power output of an AC source can the negative.
But the average power output over a cycle cannot be negative. it will always be either positive or zero.