The pressure-induced changes of the thermoelectrical power of CeRu2Ge2CeRu2Ge2 can be well described within the single-impurity Anderson model. In this model, the experimental values of the crystal-field splittings of the 4f ground state are taken into account and it is assumed that the strong Coulomb repulsion restricts the number of 4f electrons. The calculated temperature dependence of the thermopower S(T)S(T) for different hybridisation strengths and temperatures above 10 K can reproduce S(T)S(T) of CeRu2Ge2CeRu2Ge2 at different pressures. This shows, that the main characteristic features observed in other Ce- and Yb-based intermetallic systems as they are tuned, either by pressure or chemical substitution, from the magnetic to the intermediate valence regime can be explained in terms of the crossover between various fixed points of the model.