  This paper is concerned with weak solutions {e,h} in L^2 x L^2 of the
time-dependent Maxwell equations. We show that these solutions obey an energy
equality. Our method of proof is based on the approximation of {e,h} by its
Steklov mean with respect to time t. This approximation technique is well-known
for establishing integral estimates for weak solutions of parabolic equations.
In addition we prove the uniqueness of {e,h}.
