The large-scale integration of renewable energy-based power plants into the existing AC network has shown an impact on the frequency and voltage stability of the network and challenges its operation. Thus, at the common coupling point (CCP) a STATCOM and storage system are inevitable to provide the grid codes. Hence, this paper recommends a new configuration that contributes both real/reactive powers. The configuration is formed by integrating a battery storage system at the DC-link of a Modular Multilevel Converter (MMC) using a dual-active bridge (DAB). The main merits of this configuration are better efficiency, galvanic isolation for low-voltage storage modules, and lower installation costs. The control principles to manage the configuration as SESt have been proposed. The recommended controls have been validated at the CCP of a wind park using the PSCAD/EMTDC platform, and the results are persuasive.