Radial junction nanowire solar cells are expected to give a higher performance than planar junction solar cells. This is due to the enhanced optical path length for absorption, and the shorter distance for excitons to travel to interfaces where they can dissociate. By means of simulation, we have optimised, with respect to geometrical parameters, solar cells consisting of light absorber coated metal- oxide nanowires. We have primarily studied nanowires with a TiO2 core and CdSe shell, as well as ZnO cores with PbS nanoparticles. Optical scattering and absorption is determined using Finite-Difference Time-Domain (FDTD) simulations. Charge transport is studied using finite-difference drift-diffusion modelling. The generation rate calculated from FDTD is inputted into the charge transport model. The aim is to determine which combination of nanowire parameters (such as coating thickness, height, radius and spacing) lead to the the highest power efficiencies. We found that core and shell thickness has more effect on absorption than nanowire arrangement.