TITLE:
On the Development of Spatial/Temporal Solar Radiation Maps: A Minas Gerais (Brazilian) Case Study
AUTHORS:
C. Tiba, R. Reis e Reis, J. C. E. da Costa, J. F. Abreu, Melina Amoni, D. P. Guimaraes, M. A. D. Porto
KEYWORDS:
Solar Energy, Solar Irradiation Map, Solar Resource Assessment, Methodology for Mapping
JOURNAL NAME:
Journal of Geographic Information System,
Vol.6 No.3,
June
18,
2014
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.