doi:10.24084/repqj20.250engTejero, J. A.Bayod-Rújula, A. A.Haro Larrodé, M.Firm capacity of PV+STG systemsART-2022-130002The security of supply becomes a key variable of the electrical system. Due to the discontinuity of solar irradiance, PV generators are essentially not dispatchable and they operate only when there is solar resource but cannot ensure their availability when the energy is needed, so PV systems are considered having a null capacity credit. Energy storage is considered a key for the power sector and its sustainability and different options need to be exploited. The objective of this paper is analyse the optimum size of the required battery, its relations with the peak power of the generation system and the optimum operation setpoint of a PV+STG system for providing firm capacity. © 2022, European Association for the Development of Renewable Energy, Environment and Power Quality (EA4EPQ). All rights reserved.2022http://zaguan.unizar.es/record/11880810.24084/repqj20.250http://zaguan.unizar.es/record/118808oai:zaguan.unizar.es:118808Renewable Energy and Power Quality Journal 20 (2022), 155-160by-nc-ndhttp://creativecommons.org/licenses/by-nc-nd/3.0/es/info:eu-repo/semantics/openAccess