Impact of Reservoir Evaporation on Determining Power Purchasing Agreement under Solar-Hydro Hybridization

Installing floating solar photovoltaics (FPV) on reservoirs is a relatively new but rapidly emerging technology in the renewable energy sector. The combination of solar and hydro can produce fully dispatch able renewable electricity and facilitate the integration of FPV onto the grid. The benefits of solar-hydro hybridization are especially noticeable in areas with pronounced dry and wet seasons. In those areas, the evaporation loss from the reservoir cannot be ignored. This paper presents how evaporation is mathematically included in an operational hydro scheduling tool. The proposed modeling method updates evaporation loss based on the dynamic changes of the reservoir surface area. The numerical results show that less availability of water resources caused by evaporation will lead to a 7.5% reduction in maximum firm load obligation. Evaporation in solar-hydro hybridization is a vital factor that cannot be ignored when determining a reliable power purchasing agreement.