A	Area (m${}^2$)
I	Electrical current (A)
$\mathbf{J}$	Electrical current density (A m${}^{-2}$)
MFP	Mean free path
$P_{out}$	output power of TEG (W)
Q	Heat transfer rate (W)
$R_L$	Load resistance ($\Omega$)
$R_{int}$	Internal resistance ($\Omega$)
T	Temperature (K)
TEG	Thermoelectric generator
V	Voltage (V)
ZT	Figure of merit
Greek letters
$\alpha$	Seebeck coefficient (V K${}^{-1}$)
$\Delta$	Difference
$\eta$	Efficiencyv (%)
$\kappa$	Thermal conductivity (W m${}^{-1}$K${}^{-1}$)
$\mu$	Micro
$\rho$	Electrical resistivity
$\sigma$	Electrical conductivity [($\Omega$m)${}^{-1}$]
Subscripts
c	cold side of TEG element
h	hot side of TEG element
max	Maximum values
n	n-type TEG element
p	p-type TEG element