  We consider random walk among iid, uniformly elliptic conductances on
$\mathbb Z^d$, and prove the Einstein relation (see Theorem 1). It says that
the derivative of the velocity of a biased walk as a function of the bias
equals the diffusivity in equilibrium. For fixed bias, we show that there is an
invariant measure for the environment seen from the particle. These invariant
measures are often called steady states. The Einstein relation follows at least
for $d\ge 3$, from an expansion of the steady states as a function of the bias
(see Theorem 2), which can be considered our main result. This expansion is
proved for $d\ge 3$. In contrast to [11], we need not only convergence of the
steady states, but an estimate on the rate of convergence (see Theorem 4).
