  We study some features of the energy of a deterministic chordal Loewner
chain, which is defined as the Dirichlet energy of its driving function. In
particular, using an interpretation of this energy as a large deviation rate
function for SLE$_\kappa$ as $\kappa$ tends to 0 and the known reversibility of
the SLE$_\kappa$ curves for small $\kappa$, we show that the energy of a
deterministic curve from one boundary point A of a simply connected domain D to
another boundary point B, is equal to the energy of its time-reversal ie. of
the same curve but viewed as going from B to A in D.
