A simple method to calculate ground state energies for a typical condensates containing up to A ~ 107 atoms is presented. The method, based on the expansion of the wave function in terms of the Faddeev components, which in turn are expanded in terms of potential harmonics is numerically efficient. We obtain ground state results for condensates of 87Rb containing up to A → 108 atoms. The results agree very well with other methods in regions where the other methods are valid. © 2013 Springer-Verlag Wien.