| Abstract [eng] |
In this thesis, a hybrid wind and solar power plant with an energy storage system is analysed. The aim of the study is to determine the optimal ratio between the capacity of the solar power plant, wind power plant and energy storage system, taking into account the utilisation of local generation, reduction of grid imports and economic payback. The modelled system assumes that the generated electricity is first used to cover the load, surplus generation is stored in the energy storage system, and electricity export to the grid is not considered. A time-series model of the hybrid system with an hourly resolution was developed for the study. PVGIS TMY meteorological data were used to calculate solar and wind generation, while the balance between load, generation, battery state of charge and grid import was evaluated on an hourly basis. For each analysed combination of solar power capacity, wind power capacity and storage capacity, technical and economic indicators were calculated: self-sufficiency, grid import, curtailed surplus energy, investment cost, annual net savings and payback period. The scenario analysis and Pareto solution selection showed that increasing the size of the hybrid power plant and the energy storage system increases the self-sufficiency indicator; however, it also extends the payback period and increases the amount of curtailed surplus energy. The economic assessment showed that the highest economic benefit does not necessarily coincide with the highest utilisation of local generation. Therefore, the optimal solution should be selected as a compromise between technical and economic indicators. |
