  It is demonstrated that Maxwell's demon can be used to allow a machine to
extract energy from a heat bath by use of information that is processed by the
demon at a remote location. The model proposed here effectively replaces
transmission of energy by transmission of information. For that we use a
feedback protocol that enables a net gain by stimulating emission in selected
fluctuations around thermal equilibrium. We estimate the down conversion rate
and the efficiency of energy extraction from the heat bath.
