In this presentation, a methodology for the assessment of the provision of voltage regulation and power smoothing services by PV-BES systems is described, taking into account the capacity degradation of BES. The proposed framework involves quasi-static simulations incorporating the operating conditions of the distribution network. A battery aging model is used to estimate the BES capacity loss caused by both the calendar and the cyclic aging mechanisms. The updated BES capacity sets new constraints on its operation and consequently influences the efficiency of the provided ASs. The presentation is from our paper entitled “Assessing the Provision of Ancillary Services Considering BES Capacity Degradation”, presented in SEST 2022 conference and has been uploaded in our RG and LinkedIn pages.