One of the most important disadvantages of the renewable energy production in a grid scale is its dependence on the weather or local climate of the location. The weather conditions can be very changing and unpredictable in a world that depends on a constant connection to the grid. If the natural resources like sun and wind complement each other is a good opportunity to take into account the hybrid renewable power plants. In this work, centered in Spain, has been made a weather data research of 4 different locations. These locations have in common that there is already implanted a wind power plant. This interaction between resorces, suggest that a good place to install a hybrid renewable power plant is in Sierra Costera, Aragón. A power plant that complement wind power with solar PV energy. But, even combining these two resources there is still a high dependence on the weather, because there are many time periods during a year with neither sun nor wind. That is the reason why in this project has been simulated and optimized the hybrid power plant with an extra element, electric energy storage system. Once all meteorological data has been treated and interpreted, three different main parts of the project have been developed. Sizing and optimization to satisfy a constant load, development of a new power plant connected to the grid and development of a refurbishment of the wind power plant to hybridize it. In the three parts have been used Matlab to simulate the power plant behaviour with the meteorological data acquired. To satisfy a constant load has been used a methodology called Deficiency of power supply probability (DPSP) programmed with Matlab. The results on this situation show that to satisfy a constant load with a high provability, over 95 % of the time, cause an oversizing of the power plant. A lot of power installed, for a very little load satisfied. Analyzing the second situation, development of a new power plant connected to the grid, has been made an study of interaction between the variables, solar PV power, wind power, power plant capacity power and storage system capacity. The results in these interactions are good, but too expensive considering there is already a wind power plant working in the area. The third main part, development of a refurbishment of the wind power plant, has proved to be the best option. It has been simulated the profitability of this project for 15 years in 49 distinct combinations of battery systems and quantity of solar PV panels installed, helping to decide which one is the best combination. The energy shared to the grid has increased over 100 % and the battery system helps to decrease the energy wasted because of the power plant main transformer capacity.