Análise de viabilidade econômica de um projeto de investimento em usina fotovoltaica no ambiente de contratação livre na modalidade de autoprodutor: um estudo de caso

Abstract

Given the number of Brazilian companies that are migrating to the Free Energy Market and the constant change in electricity sector legislation, companies need to evaluate technical and financial factors to guarantee the economic viability of their projects and make well-founded investment decisions. The purpose of this study was to analyze the economic viability of three different scenarios of self-production of electrical energy with the installation of photovoltaic generating plants for an electro-intensive company, located in the Southwest region of Paraná, to become a self-producer of electrical energy. The starting point was to analyze the documentation and information provided by the company to find out its characteristics and current electricity demand. The company belongs to consumption group A, due to the voltage being higher than 2.3 kV and is classified as a free consumer of electricity under a contract negotiated within the Free Energy Market. In the study, the sizing of the generating plants necessary to meet the company's electricity demand was carried out in each proposed scenario, namely: 25%, 50% and 100% of photovoltaic self-production. During the calculations of the physical space required to install the generating plants, the company's roof area was limited. As the installation of minigeneration on site was not viable for the scenarios analyzed, it was considered using another available location in the city of Pato Branco for the installation, having self-production remotely. The operating and maintenance costs of the systems were then estimated to project the savings resulting from these Investment Projects (IP). Next, an Economic Feasibility Analysis (AVE) of the PI in each case was carried out, using the Expanded Multi-Index Methodology (MMIA), and if necessary, the Monte Carlo Simulation (SMC) via the free access application $AVEPI®. Based on the main results of the indicators, it was possible to analyze the unfeasibility of each scenario studied. In addition to the MMIA, Sensitivity Analysis (SA) was used, which made it possible to quantify in a stochastic way the impacts of variations in inputs on the unfeasibility of the IP. The economic unfeasibility of the projects was observed in the three scenarios analyzed, due to the high interest rates and high initial investment costs. For IPs to become economically viable, a minimum reduction of 30% in the values of fees and initial investment costs would be necessary. It was also noted that, with the investment in a location different from the company's measurement, the characteristics of remote self-production made the investment in the proposed scenarios economically unfeasible, due to the fact that net measurement continues to be billed in full by the electricity concessionaire that serves the company in question. Therefore, it was defined in this case study that the presented scenarios of remote self-production must be discarded, starting with the idea that generation needs to be local, at the load, a scenario in which the instantaneous reduction of all or part of the energy generated occurs, affecting the metering charge is payable only in the case of purchased electricity. This study offers a methodology applicable to other cases, helping companies to evaluate the economic viability of self-production of energy, considering the specificities of each scenario.