The presence of electric vehicles in the world fleet has rapidly increased in the last decade. Car manufacturers are increasingly moving toward a transition from combustion-powered vehicles to electric power. In addition, new international agreements for energy sustainability have signed between governments, resulting from the growing public awareness in relation to the environment, making the presence of electric vehicles in the streets gain even greater momentum. In Brazil, this movement is still in its initial phase, but it is on the same path as the most advanced countries in this segment. Major car manufacturers have begun to introduce this type of vehicle in the Brazilian market in increasing numbers in the last years. However, as the first lots of hybrid and electric vehicle batteries are reaching retirement age, efficient means of reusing these batteries is becoming increasingly relevant. The Tarifa Branca, in turn, is a new energy tariff module in which there is a variation of the energy price according to the time of day. It will be available to any consumer unit, regardless of its monthly consumption, starting 1st of January 2020. This thesis proposes the construction of a stationary storage unit, to be applied in residential complexes, allowing the consumption of electricity only at the cheapest tariff periods, allowing consumers who join the system to save on monthly electricity expenses. The focus of the study is on the construction of a stationary storage unit that uses the retired battery of an electric vehicle. Several assumptions such as the battery conversion cost and its degradation over its second life are considered in the analysis of the project s financial viability. The results obtained in the final simulations were very promising. The project implementation proved to be quite feasible under the proposed conditions. It was possible to extract a good 13 years of use of the storage system as well as a considerable profit on the initial investment.