Simulation and analysis of a stand-alone solar-wind and pumped-storage hydropower plant

• Evaluation of a renewable hybrid power plant for off-grid autonomous operation.
• Combination of a pumped-storage hydropower plant, PV cells and wind turbines.
• Energy surplus is used in an electrolyzer to generate hydrogen.
• The mean annual efficiency of the hybrid plant is found to be 14.4 %.
• Operation with output restrictions, capacity oversizing and storage facilities.

This work presents the simulation and evaluation of a renewable hybrid power plant for off-grid fully autonomous operation on an intermediate-sized island in the Aegean Sea. A stand-alone energy system including storage facilities is simulated, optimized and analyzed relying on real-case weather and demand data of a relatively large remote community. Optimization of the power plant structure shows that to ensure continuous off-grid energy generation, even under extreme conditions, the combination of more than one renewable technology is required. The hybrid power plant consists of a pumped-storage hydropower plant, photovoltaic cells and wind turbines. Energy surplus of the power plant is used in the incorporated electrolyzer to generate a secondary product, hydrogen. Robust operation of the plant results in 48% of the energy generated stemming from the photovoltaic system and 52% from the wind turbines. The pumped-storage hydropower plant has a mean annual power output of 1.0 MW. The total mean annual efficiency of the hybrid plant is found to be 14.4%. Although stand-alone operation was achieved with the proposed plant, this requirement led to net energy output restrictions, capacity oversizing and large storage facilities.