In Brazil, there are many projects in photovoltaic systems, and the projection for the coming years is positive due to the government incentives and the expensive energy tariffs. Associated with this, the Lithium-ion battery storage systems market has been promising due to a significant drop in battery prices in the last few years. This may represent an opportunity for the photovoltaic system market when the incentives run-out. This work proposes a stochastic mixed integer linear programming (MILP) model to design a photovoltaic system integrated with battery energy storage for big electricity consumers, using generation and consumption scenarios, being able to consider different Time-of-Use tariffs. The decision variables are the number of panels, inverters and batteries, its daily operation and the power demand contracted. The objective function aims to minimize the cost of investment, in the photovoltaic system, batteries and electricity bill. The proposed approach will be analyzed under different assumptions, one with the government incentive about injected surplus and another in which the injection into the network is not possible, in order to assess the importance of a storage system to keep the economic attraction of the photovoltaic system. Results indicated that the synergic effect of the photovoltaic system and battery potentialize the arbitrage, which is related to the difference between peak and off-peak energy tariff. This occurs, mainly with Zero Export operation because only this way the consumer is free to choose the capacity of the photovoltaic system, which is limited in Brazil when the system is allowed to inject energy into the network.