Abstract. Motivated by recent discovery of strongly spin-orbit coupled twodimensional (2D) electron gas near the surface of Rashba semiconductors BiTeX (X=Cl, Br, I), we calculate thermoelectric responses of spin polarization in 2D Rashba model. By self-consistently determining the energy-and subband-dependent transport time, we present an exact solution of the linearized Boltzmann equation for elastic scattering. Using this solution, we find a non-Edelstein electric-field induced spin polarization which is linear in the Fermi energy E F , when E F lies below the band crossing point. The spin polarization efficiency, which is the electric-field induced spin polarization divided by the driven electric current, increases for smaller E F . It is shown that, as a function of E F , the temperature-gradient induced spin polarization continuously increases to a saturation value when E F downs below the band crossing point. As the temperature tends to zero, the temperature-gradient induced spin polarization vanishes.