In this work we compare different approaches to compute absorption properties of two model chromophores (two thioester analogs of the photo-active yellow protein (PYP) chromophore) in different solvent environments. For this we will rely on the standard PE approach and here investigate the requirements regarding the size of the QM system in order to reach results comparable to full QM calculations. Next, we will investigate the possibility of reducing the size of the QM region by coupling the PE approach to the exciton picture.