  Effective Capacity (EC) indicates the maximum communication rate subject to a
certain delay constraint while effective energy efficiency (EEE) denotes the
ratio between EC and power consumption. In this paper, we analyze the EEE of
ultra-reliable networks operating in the finite blocklength regime. We obtain a
closed form approximation for the EEE in Rayleigh block fading channels as a
function of power, error probability, and delay. We show the optimum power
allocation strategy for maximizing the EEE in finite blocklength transmission
which reveals that Shannon's model underestimates the optimum power when
compared to the exact finite blocklength model. Furthermore, we characterize
the buffer constrained EEE maximization problem for different power consumption
models. The results show that accounting for empty buffer probability (EBP) and
extending the maximum delay tolerance jointly enhance the EC and EEE.
