On the Development of Spatial/Temporal Solar Radiation Maps: A Minas Gerais (Brazilian) Case Study

C. Tiba, R. Reis e Reis, J. C. E. da Costa, J. F. Abreu, Melina Amoni, D. P. Guimaraes, M. A. D. Porto

Companhia Energética de Minas Gerais, Belo Horizonte, Brazil.
Embrapa Milho e Sorgo, Sete Lagoas, Brazil.
Nuclear Energy Department, Federal University of Pernambuco, Recife, Brazil.
Programa de Pós-Gradua??o em Geografia, PUC, Belo Horizonte, Brazil.

DOI: 10.4236/jgis.2014.63024                

Abstract

Appropriate information on solar resources is very important for a variety of technological areas, such as agriculture, meteorology, forestry engineering, and water resources, particularly for an innovative technology such as solar energy. In the market entry process of an innovative technology such as solar energy, the increased and sustained deployment of this energy technology strongly depends on the economy and reliability of the solar systems installed. The economy and reliability of a system are the consequences of a well-prepared project, resulting from an accurate knowledge of the solar resource available. Therefore, knowing the potential of the solar resource accurately is not only a need but also an imperative for the larger diffusion and use of the solar energy. The existing sources of the information on radiation in MG are quite varied, both at the institutional level and in different types of publications. The publications containing this information are project reports, internal reports of institutions, and several magazines. Thus, the quality of the data varies considerably, the information presents spatial and temporal discontinuity; moreover, the instruments and the measurement units are not standardised. The general objective of this paper is to recover, to qualify, to standardize, and to make available the best information from the current existing solar resource in MG, Brazil, either in the form of isoline charts of solar radiation or a numerical database. In this paper, the procedure to elaborate the maps of daily solar radiation and insolation, along with the monthly and annual averages, is described. We present one map with the localisation of the recording stations in addition to one annual and 12 monthly contour maps. The map of the daily global solar irradiation and the annual average determined in this project show that solar radiation on the state of Minas Gerais ranges from 4.5 to 6.5 kWh/m². The maximum values occur in the northern region of Minas Gerais, and the minimum values occur in the southeast region, where there are areas of higher altitude (Mantiqueira and Serra do Caparaó) and the rainfall is more intense, with total annual rainfall greater than 1400 mm. The North and Northeast Regions of MG, where the largest annual irradiation of 6.5 kWh/m² occurs, are characterised by a semiarid climate with annual rainfall between 600 - 800 mm and altitudes between 400 - 600 m. The maritime tropical air mass that acts between Brazil and Africa is the main climatic factor that inhibits cloud formation and, consequently, the rainfall in this region. Finally, the map of annual insolation reveals a consistent correlation between the daily rainfall and the solar radiation annual average.

Keywords

Solar Energy, Solar Irradiation Map, Solar Resource Assessment, Methodology for Mapping

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	IBGE—Instituto Brasileiro de Geografia e Estatistica (2010) Pesquisa Nacional por Amostra de Domicilio (PNAD), Brasilia/DF.
[2]	Vernich, L. and Zuanni, F. (1996) About the Minimum Number of the Years Required to Stabilize the Solar Irradiation Statistical Estimates. Solar Energy, 57, 445-447. http://dx.doi.org/10.1016/S0038-092X(96)00121-1
[3]	Gallegos, H.G. and Lopardo, R. (1988) Spatial Variability of the Global Solar Radiation Obtained by the Solarimetric Network in the Argentine Pampa Humeda. Solar Energy, 40, 397-404. http://dx.doi.org/10.1016/0038-092X(88)90094-1
[4]	Angstrom, A. (1924) Solar and Terrestrial Radiation. Quarterly Journal of the Royal Meteorological Society, 50, 121-126. http://dx.doi.org/10.1002/qj.49705021008
[5]	INMET—Instituto Nacional de Meteorologia (2010) Brasilia/DF, 1961-1990 e 2009-2010.
[6]	INPE—Instituto Nacional de Pesquisas Espaciais (2010) Brasilia/DF, 2008-2010.
[7]	CEMIG (1987) Estudos sobre Aproveitamento de Energias Solar e Eolica em Minas Gerais, Depto de Tecnologia de Engenharia, 01.000-TN/TE-093, Relatorio Tecnico de Projeto.
[8]	Tiba, C., Grossi Gallegos, H., Fraidenraich, N. and Lyra, F.J.M. (1999) On the Development of Spatial: Temporal Solar Radiation Maps: A Brazilian Case Study. Renewable Energy, 18, 393-408. http://dx.doi.org/10.1016/S0960-1481(98)00806-4
[9]	Colle, S. and Pereira, E.B. (1998) Atlas de Irradiacao Solar do Brasil—Primeira versao para irradiacao global derivada de satelite e validada na superficie. Edicao. Florianopolis: LABSOLAR/NCTS, 79-104.
[10]	Burrough, P.A. and Mcdonnell, R. (1998) Principles of Geographical Information Systems. Oxford University Press, New York, 333.
[11]	Abreu, J.F. and Barroso, L.C. (2003) Geografia, modelos de analise espacial e GIS. Pontificia Universidade Catolica de Minas Gerais (PUC Minas), Belo Horizonte.
[12]	Watson, D.F. (1992) Contouring: A Guide to the Analysis and Display of Spatial Data: With Programs on Disket. Pergamon, Oxford, 321.
[13]	Tobler, W.R. (1979) Smooth Pycnophylactic Interpolation for Geographical Regions. Journal of the American Statistical Association, 74, 519-536. http://dx.doi.org/10.1080/01621459.1979.10481647
[14]	Comber, A., Proctor, C. and Anthony, S. (2007). A Combined Pycnophylactic Dasymetric Method for Disaggregating Spatial Data: The Example of Agricultural Land Uuse. Proceedings of the Geographical Information Science Research UK Conference, National Centre for Geocomputation, National University of Ireland: Maynooth, 445-450.