This paper presents the first results of a R&D Project financed by a Brazilian company called Paulista Company of Power and Light. The main project’s objective is to investigate the use of battery storage applied to a real wind farm. It is known that the storage connected to a wind farm can provide several services to the electric grid, such as: power smoothing, frequency regulation, voltage stabilization, power factor regulation, time shift and black start etc. They are important to improve the financial balance as each service lead to revenues. A Lidar (Light Detection And Ranging) was installed in the wind farm to measure the wind speed passing through the wind turbines, and thus determine the available energy, as well as its energy availability curve over time. Five power quality analyzers were also installed in order to measure the power production from wind farm. The preliminary results and analysis of these data, shows that the sizing and designing the storage system is not directly related to the wind power installed. That proves that there is cancelation of peaks from each wind turbine in the total result, leading to an important point that a storage of 20MW would eliminate 100% of power fluctuations intra hour of a 100MW wind farm, a storage with 5MW would remove 98%. The Lidar also subsidize some results in determining the fluctuation in the wind conditions that has been showing a good behavior even the wake effect was reduced in the park not showing the expected cone shape but a cylindrical shape reducing the effect on the near wind turbines. For this project, a lithium battery with 1% of the installed wind farm capacity has been installed and will be possible to test different operation modes. Further, for technical and economic analysis the adjustment will be done mathematically. Also, it will contribute to prove the best sizing of the energy storage system and contrast with the literature. The next steps are commissioning and testing the system. The current regulation does not value the possible services provided by the battery. Calculations made so far, using current regulation, show that the use of lithium batteries, at the current cost, for the purpose of this project is not economically viable. Within the scope of the project, there is an evaluation of the regulation. It makes possible to propose a fair valuation of the services provided by the batteries in order to bring financial balance to the use in wind farms.