Electrification of rural areas is one of the major challenges in countries of the Global South. A proper electrification planning requires comprehensive electrification modelling to understand the least-cost supply options. Within this paper we apply a literature research on the requirements of comprehensive electrification modelling. This is extended by research on and testing of existing modelling tools (HOMER Energy, Network Planner, GEOSIM). This analysis reveals that still none of the existing tools can fulfill all requirements combining geospatial and detailed power system modelling especially for hybrid mini-grids. Thus we present our newly developed electrification modelling approach which overcomes the existing gaps.