This paper proposes an aggregated approach for the technical and economic assessment of battery energy storage systems (BESSs) in congested distribution grids (low voltage and medium voltage). For this purpose, the usage of BESS to avoid or temporally shift grid extensions is analyzed and compared with other technical measures such as grid extensions, innovative grid equipment, and feed-in curtailment. A combined optimization approach is used to identify jointly optimal economic decision of grid and storage operators. The investigations highlight the economic competitiveness of BESS, compared to other measures, when additional participation of BESS in wholesale market is allowed. It is shown that optimal decisions for grid development are strongly dependent on key grid parameters like line length and level of excess photovoltaic-feed-in. Moreover, the applied regulations, e.g., renewable curtailment rules, are found to impact considerably on the optimal decisions. The proposed methodology is, in contrast to existing approaches, suitable for the investigation of large varieties of grid configurations and grid utilizations with limited efforts. It thus allows identifying situations, in which the application of BESS in distribution grids is most effective. Moreover, it enables a thorough assessment of the impact of regulatory changes given large heterogeneity of existing distribution grids.