3D software package for designing photovoltaic systems under partial shading conditions

• Grant number: 18/07631-0
• Support Opportunities: Research Grants - Innovative Research in Small Business - PIPE
• Start date: February 01, 2019
• End date: November 30, 2019
• Field of knowledge: Engineering - Electrical Engineering
• Principal Investigator: Luís Carlos Lorenzo Acácio
• Grantee: Luís Carlos Lorenzo Acácio
• Company: Virtux Energia Solar Ltda
• CNAE: Pesquisa e desenvolvimento experimental em ciências físicas e naturais
• City: São Paulo
• Pesquisadores principais: Rogério Guerra Borin
• Associated scholarship(s): 19/02123-9 - 3D software package for designing photovoltaic systems under partial shading conditions, BP.TT; 19/02244-0 - 3D software package for designing photovoltaic systems under partial shading conditions, BP.TT; 19/02117-9 - 3D software package for designing photovoltaic systems under partial shading conditions, BP.PIPE

Abstract

The proposal of our research plan is the development of a scientifically founded 3D software for the design of photovoltaic systems well suited for the Brazilian market needs. One of the first tasks of a photovoltaic systems integrator when he approaches a potential client, is the assessment of how much electrical energy can be produced. This analysis is based on many factors, such as: 1. energy consumption by the client; 2. cost of energy to the client; 3. available area for installing the panels; 4. location and positioning of the premises; 5. tridimensional environment of the premises; 6. behavior of photovoltaic panels and inverters; 7. solar irradiance at the client location. Our goal is to develop a design software that attack all those points simplifying the work of photovoltaic systems integrators. Such a task is far from merely software implementation, although there are options in the market they are all mysterious black-boxes whose principles may be known but the details are certainly not. These details have to be rediscovered by rigorous research every time someone adventures in its execution. In order to offer an idea of the difficulties involved in this work, particularly items 4 to 7 above, we make the following comments: => Solar irradiation data are always supplied as daily mean along each month of the incidence over a horizontal surface free of shading and with a unobstructed horizon; almost always an unrealistic situation. => Extrapolations are required to convert the ideal situation data to the real conditions of the client. => It is necessary to reproduce in a computational platform the tridimensional environment of the client premises and calculate the shadows cast over the solar panels at every hour of the day along a whole year. => Since any point on Earth receives 4,380 hours of sunlight in a regular year, that same figure is the number of required simulations to evaluate energy generation. => The extrapolations require decomposition of the solar irradiation in the basic components: Direct, Diffuse and Reflected. => There are many different algorithms in the technical literature for the decomposition of solar irradiation in the basic components, it is necessary to list and test them. => Since the decomposition is made by empiric methods scientifically based, different results may be obtained in different regions; a criterious selection is required. => The next step is to simulate the behavior of solar panels under partial shading. => Under uniform shading, solar panels behave linearly, but under partial shading the response is strongly non-linear causing great difficulties to energy yield estimates. => Given the complex behavior of solar panels under partial shading, the technical literature is abundant with simulation techniques; it is necessary to test them. => In Brazil, the most reliable solar data are those provided by INPE - Instituto Nacional de Pesquisas Espaciais (National Institute for Space Research). => We plan to find out which data is available to INPE but still unpublished, which could be used to enhance the estimates of energy yield. => We have already stablished a promising initial contact with INPE and checked that there are hourly data in crude format which are available but require further treatment for use. => It is one of our goals to analyze those data and to integrate them in our software taking photovoltaic energy yield estimates in Brazil to an all-time high quality level. (AU)