Reunião Regional da SBPC em Oriximiná

A. Ciências Exatas e da Terra - 3. Física - 7. Física Geral

CONVERGENT LENS: A METHOD FOR OPTIMIZATION OF PHOTOVOLTAIC SYSTEMS WITHIN THE AMAZON

Márlison de Sá Rêgo 1 Sebastião Douglas Avelino Burgos 1 Manoel Roberval Pimentel Santos 2

1. Graduando / Universidade Federal do Oeste do Pará – UFOPA 2. Prof. Dr. / Advisor - Universidade Federal do Oeste do Pará – UFOPA

INTRODUÇÃO:

Photovoltaic solar energy is to transform the energy carried by light from the sun into electrical energy from photovoltaic modules that work through the process known as Photovoltaic Effect, discovered by Alexandre-Edmond Becquerel (1839). This form of energy already enjoys status as a significant source of clean, renewable energy, plus it has the peculiarity of the individual and independent energy supply. This makes it ideal to meet the electrical demands of geographically isolated regions, such as the rural communities of the lower Amazon. However, the high cost of the photovoltaic modules restrict the quality of the generated energy in order to prevent the acquisition of managed systems and automation satisfactorily. Thus, even in these places there is electricity, its use will be limited to meet priorities, which generally relate to cooling, lighting and transportation of water resources. Therefore this study used a method of optimization of photovoltaic systems by altering the radiative density incident on a PV module by the interpolation of a converging optical lens from a photovoltaic cell and the sunlight incident.

METODOLOGIA:

Initially we created a vertical structure and connected to it, perpendicularly, a foundation that sought support for the two systems would be set on it. Both systems consisted of two photovoltaic cells: an optimized convergent optical lens radius 4 cm and the other under it without the apparatus of the solar cell before. In both cells, which were connected ammeters were adjusted in the range of milliampere (mA). Then, we place this instrument in 2°25ʼ07.18" South, 54°44ʼ31" West, which is in itself the University Campus. The basis on which are placed the two systems take into consideration the sun relative movement earth, and therefore could rotate up to 180 ° so that the cells could keep always directed to the incident light rays, the angle of inclination could be verified in protractor attached to the base. Then, at intervals of 15 minutes over a typical day of summer, we direct the structure to the sun and take measurements of electric current. The following data were tabulated in a spreadsheet and culminated in the chart that listed current (mA) and time (h) of two photovoltaic cells, where we find the correlation optimization.

RESULTADOS:

The data analysis allowed to verify some aspects characteristic interaction of solar radiation and Amazon atmosphere, as well as to establish the correlation optimization. The curves obtained from the relation current (mA) and time (h) described a Gaussian form, since this would be expected taking into account the variation of the radiation incident on the cell throughout the day. We also found, among some intervals, the sudden drop in current of both devices, this occurred because of a striking feature in the Amazon region which is the formation of clouds, which absorb radiation in almost all wavelengths long, to be formed water, and because of the albedo reflecting radiation to the upper atmosphere. But the main result was the correlation optimization, which showed that the photovoltaic system optimized exceeded, on average, 40 times the conventional photovoltaic system. This implies that when we increase the density per mm2 luminous efficiency of the system increases. However, to increase the efficiency of the cell order of light intensity, can damage the equipment. In European systems that use this logic optimization, the converging lens is developed in every cell of PV module with an efficiency lower than that obtained in this experiment, but with a more promising life.

CONCLUSÃO:

As we know the solar modules are composed of several identical photovoltaic cells constructed from semiconductors, within them there is an intrinsic electric field. The light focused on these cells transfers part of its energy to the electrons present, which by becoming more energy, release from the atomic attraction, making it free. This condition allows the internal field of the cell put in the orderly movement, thus creating the so-called electric current, which is responsible for the operation of electronic devices. Thus, the method of optimization of photovoltaic systems by converging lenses, showed that by altering the radiative density on the photovoltaic cell, we are actually multiplying the amount of light falling per unit area of the photovoltaic module, it affects the excitation of a number more electrons and, consequently, a higher electrical current. Thus, the efficiency of the photovoltaic system is enhanced and may provide more accurate, for example, the energy demands of isolated communities of the lower Amazon.

Palavras-chave: Amazon Context