The prospect of declining prices in photovoltaic systems and battery energy storage systems has brought about the possibility of greater economic viability for projects involving distributed energy resources. In Brazil, Regulatory Resolution 482/2012 regulated micro and mini distributed generation, thereby encouraging the integration of these resources into distribution networks. With the enactment of Brazilian Law 14.300/2022, projects involving micro and mini distributed generation were impacted, as the net metering system for electricity became partial, demanding the addition of value to distributed generation-based business models. This work proposes a stochastic Mixed Integer Linear Programming model aimed at evaluating the economic feasibility of virtual power plants composed of different configurations of distributed energy resources, involving batteries and photovoltaic panels. To achieve this purpose, the model seeks to size the optimal annual energy contract, also providing the daily operation of the batteries. In addition to considering the aspects of Law 14.300/2022, the model incorporates tariff arbitrage practice, thus contributing to studies analyzing regulatory impacts on ventures involving batteries and photovoltaic panels in the Brazilian context. In order to comprehensively address the topic, the proposed model was implemented for distributed energy resources organized as virtual power plant, containing: (i) a photovoltaic system; (ii) a battery energy storage system; (iii) a hybrid system (composed of a photovoltaic system and a battery energy storage system); and (iv) the case study of the Brazilian electric utility Energisa Tocantins. In all applications, the economic viability of the virtual power plant was analyzed for the tariffs of Energisa Tocantins and 34 other Brazilian distributors, representing at least one distributor per Brazilian state. Additionally, comparisons were made regarding the start date of operation of the virtual power plant, highlighting the impact of Law 14.300/2022 on the economic viability of the analyzed virtual power plants, thus demonstrating the impact of said law on distributed generation projects in Brazil. In the case study of the Brazilian electric utility Energisa Tocantins, an additional analysis was conducted considering aspects of Energisa Tocantins distribution network, where distributed energy resources are allocated. In this additional analysis, electrical losses and their costs, as well as voltage profiles for two battery operation scenarios and the base case (i.e., the case without distributed energy resources in the Energisa Tocantins distribution network) were evaluated. The results showed that the implementation of Law 14.300/2022 reduced the attractiveness of projects involving distributed generation. However, for the most part, considering the parameters adopted in this study, these projects still demonstrate economic viability. Taking into account electrical losses and voltage profiles, the integration of distributed energy resources into the distribution network can bring electrical benefits and cost reductions, depending on the operation of the distributed energy resources, demonstrating their ability to provide ancillary services to the electrical system. Furthermore, photovoltaic systems still exhibit greater competitiveness when compared to hybrid systems or battery energy storage systems, providing more attractive financial returns. Finally, different tariff amplitudes directly influence the viability of distributed generation projects involving energy storage systems, as the greater the tariff amplitude, the greater the tariff arbitrage that such systems can provide.