Assessing Operational Behaviour of a Hybrid Hydro-Solar Power Plant Providing Security of Supply Under Weather Uncertainty in the Nordics

This paper presents a medium-term scheduling model of a hybrid hydro-solar power plant. The study examines how hybridization enhances the security of supply of a hydro-only system, particularly in Nordic weather conditions. A stochastic dynamic programming (SDP) algorithm is implemented to properly address the uncertainty of Nordic weather conditions and calculate water values. With solar power modeled as a photovoltaic (PV) installation, a hybrid system was created to optimize the load fulfillment. The results from the hybrid system were compared with the reference hydro-only system and an energy-upgraded hydro-only system using a creek inlet. The Ormsetfossen power plant, a Norwegian hydropower system with two reservoirs, is used as a reference for the data collection and topology modeling. Scenarios from 30 weather years of inflow and solar irradiation data were used to produce production plans for the hybrid and hydro-only configurations. Results indicate that hybridization enhances the security of supply to a greater extent than the energy-upgraded hydro-only system. The energy- upgraded hydro-only system is on the other hand more self-sufficient and less reliant on power imported from the market.