Authors: Rafael de Almeida Santos & Gabriele Costa Gonçalves
Energy Review, Vol 4. Issue 7. 2022
Brazil, a developing country, follows the same trend as the developed countries, in which it is expected that there will be a growth in electricity consumption proportional to the development of its economy along with the emergence of new technologies. According to the energy research company (EPE), in the year 2019, Brazil has shown a progression of 1.3% in the final demand for electricity, and the sectors that contributed most to this progression, in terms of absolute values, were commercial (+4.5%), residential (+3.5%), energy (+4.1%), and public (+2.1%). Brazil, in a positive way, contrary to the world average, presents an electric energy generation matrix of predominantly renewable energy sources, responsible for approximately 85% of electricity generation.
However, there is a strong dependence on hydroelectric generation which accounts for more than 65% of the electricity supply. The expansion of hydroelectricity comes up against the fact that Brazil's unexploited hydroelectric potential is found in the Amazon region, involving environmental issues. Based on the data, it is possible to affirm that the consumption of electric energy in Brazil is growing annually. However, hydroelectric plants are not being constructed in the same proportion. Further, the low occurrence of rainfall in the last Brazilian summer has significantly reduced the water level of the reservoirs of the hydroelectric plants. This has contributed to a considerable increase in electricity tariffs throughout the country and has also generated a greater negative environmental impact caused by the greater use of non-renewable power plants.
With the intention of redirecting the conventional electric power generation methods to the non-conventional ones, the development of the use of new renewable sources is being sought. In that context, the participation of solar energy has been becoming more and more frequent in mainly the residential sectors and small and medium companies. This is relevant because it raises discussions about smart grids and encourages, in a considerable way, discussions about increasing the participation of renewable sources in the world's electricity matrix. A relevant issue of decentralization consists of the consumer being able to generate their own electricity through small-sized power plants, called Micro and Mini-generation Distributed - MMGD. MMGD is backed by the Normative Resolution of the National Electric Energy Agency (ANEEL) No. 482/2012, which allows Brazilian consumers to produce their own electricity from qualified cogeneration or renewable sources.
According to Portal Solar, the number of photovoltaic system installations has grown exponentially in the country, standing out with a 1.7% representativeness in the national energy matrix, against the distributed generation of approximately 3 GW of power installed throughout Brazil. According to ABSOLAR, in the year 2021, Brazil will have an installed capacity of 8.47 GW, corresponding to 7% of all the power coming from water resources. It is in this conjuncture that the present work aims to propose a system for generating electricity through solar energy and evaluate the impacts of the average annual consumption and energy billing of the campus of Science and Technology in Energy and Sustainability (CETENS) of the Federal University of the Reconcavo da Bahia (UFRB). To this end, the methodology used was qualitative in nature, in which a literature review was conducted in order to answer the relevant questions and spread knowledge about PV’s, identifying the necessary and appropriate tools for its adequacy in the current scenario since the idealization, operation and results to obtain a sustainable and economically viable system of electricity generation. In the survey of publications relevant to the theme and the research objectives, documents, manuals and federal legislation that regulate the implementation and structure of the systems were selected, along with meteorological research that indicated the climatic reality in which the city of Feira de Santana, the city that hosts the CETENS campus, is located.
In this way, the present work studies the photovoltaic systems as a model of solar energy generation for an energetic invoicing of, approximately, BRL 120 thousand per month that is responsible for supplying the energetic demands of CETENS. In this circumstance, it is necessary to obtain a system with power around 270 kWp and that, once applied, can reduce the energy consumption of the campus by up to 95%, making it self-sufficient. Once applied and in operation, the PV provides the institution with a Return on Investment (ROI) in a period of 10 years. The conclusion is that, for the remaining 15 years of useful life of the equipment implemented in this project, the UFRB campus would have a credit close to the value of 2 million BRL - an amount that can be redirected as a form of investment in new technologies to improve the quality of electric energy in the institution or even in the development of the campus as a whole. Thus, it is evident that the system is capable of supplying the consumption in its majority, besides being possible to generate credits with the local energy distribution concessionaire, bringing stability in the billing for the months with low generation index linked to climatic factors.
(Mr. Rafael de Almeida Santos is a student of the Energy Engineering course, and Dr. Gabriele Costa Gonçalves Dantas is Professor at the Energy Energineeng Department at Universidade Federal do Recôncavo da Bahia (UFRB), Brazil.)