  An analytical model is presented that can account for both electrical and hot
and cold thermal contact resistances when calculating the efficiency of a
thermoelectric generator. The model is compared to a numerical model of a
thermoelectric leg, for 16 different thermoelectric materials, as well as the
analytical models of Ebling et. al. (2010) and Min \& Rowe (1992). The model
presented here is shown to accurately calculate the efficiency for all systems
and all contact resistances considered, with an average difference in
efficiency between the numerical model and the analytical model of
$-0.07\pm0.35$ pp. This makes the model more accurate than previously published
models. The maximum absolute difference in efficiency between the analytical
model and the numerical model is 1.14 pp for all materials and all contact
resistances considered.
