Coupling hydro and wind electricity production by water - pumping storage

We quantify the capability of coupling wind farm and hydraulic plant, in view to produce energy without fluctuations, like wind farm alone. In fact, we suppose the hydraulic plant is like a buffer, and the wind farm fed this buffer. The aim is to satisfy a certain quantity of energy, more particularly, a percentage of the peak load. We can so optimize the system : power of the wind farm with the power of the hydraulic plant.