The Combination of Energy Storage and Renewable Energies to Reach a Maximum Profit for Power Systems

This paper investigates the effectiveness of the water storage and electricity generation of a pumped-storage hydroelectric plant (PSP) for maximizing total electricity sale revenue of one day as it is integrated into a hybrid power system with the presence of wind power plants (WP) and solar photovoltaic power plants (SP). Four study cases with different rated powers of PSP, including 50, 75, 100 and 125 MW, are implemented to find the most suitable capacity, the optimal hours for water storage and the optimal generation for other hours of the considered PSP. Similarly, the four cases are also investigated for another hybrid power system with the same WP and SP, but PSP is replaced with another conventional hydroelectric plant (CHEP), which does not have a storage function. Five optimization algorithms, including Slime mould algorithm (SMA), Equilibrium optimizer (EO), Jellyfish Algorithm (JS), Coot optimization algorithm (COOT) and War Strategy optimization Algorithm (WSO), are implemented for two hybrid power systems. As a result, EO is the highest performance method with superiority over others in almost all cases. The second hybrid system with PSP can reach a greater revenue than the first hybrid system with CHEP by ${\$}31,638$ , which is about 11% of the total revenue of the first system. In addition, the second system only uses a PSP with a rated power of 75 MW, but the first system must use a higher rated power of 100 MW for CHEP. Clearly, PSP is very effective for hybrid power systems with the integration of renewable power plants in reaching maximum total revenue. However, the comparisons among study cases also indicate that the rated power of PSP should be carefully calculated, otherwise, PSP is no longer applicable.