Abstract The paper presents a new type of Renewable Energy Sources (RES) suitable for exploitation watercourse with periodical-temporary water flow. This innovative solution consist of Hydroelectric Plant (HEP) and solar Photovoltaic (PV) generator working together as one hybrid power plant, producing green energy with the same characteristics as classical hydroelectric plants. The main objective of this hybrid solution is achievement of optimal renewable energy production in order to increase the share of RES in an Electricity Power System (EPS). As a paradigm of such exploitation of RES, the example of HEP Zavrelje/Dubrovnik in Croatia was used, where it was ascertained that the proposed solution of hybrid PV-HEP system is natural, realistic and very acceptable, which enhances the characteristics of both energy sources. The application of such hybrid systems would increase the share of high quality RES in energy systems.