Tidal surface heating rates, including eccentricity and obliquity heating, on Gl581 d (left panel) and Gl581 g (right panel) following the model of Lec10 as a projection on the parameter plane spanned by obliquity ψ_p and eccentricity e. Equilibrium rotation of the planets is assumed. The observed eccentricity of 0.38   ( ± 0.09) for Gl581 d (Mayor et al. 2009) is indicated with a dashed line, while the eccentricity of Gl581 g is compatible with 0. Depending on obliquity, tidal surface heating rates on Gl581 d vary between roughly 2 and 15 mW/m², while on planet candidate g they are < 150 mW/m² as long as e ≲ 0.3.