A methodology for downscaling solar irradiation from satellite-derived databases is described using R software. Different packages such as raster, parallel, solaR, gstat, sp, and rasterVis are considered in this study for improving solar resource estimation in areas with complex topography, in which downscaling is a very useful tool for reducing inherent deviations in satellite-derived irradiation databases, which lack of high global spatial resolution. A topographical analysis of horizon blocking and sky-view is developed with a digital elevation model to determine what fraction of hourly solar irradiation reaches the Earth's surface. Eventually, kriging with external drift is applied for a better estimation of solar irradiation throughout the region analyzed including the use of local measurements. This methodology has been implemented as an example within the region of La Rioja in northern Spain. The mean absolute error found using the methodology proposed is 91.92 kW h/m2 vs. 172.62 kW h/m2 using the original satellite-derived database (a striking 46.75% lower). The code is freely available without restrictions for future replications or variations of the study at https://github.com/EDMANSolar/downscaling.

1.
Alsamamra
,
H.
,
Ruiz-Arias
,
J. A.
,
Pozo-Vázquez
,
D.
, and
Tovar-Pescador
,
J.
, “
A comparative study of ordinary and residual kriging techniques for mapping global solar radiation over southern Spain
,”
Agric. For. Meteorol.
149
(
8
),
1343
1357
(
2009
).
2.
Antonanzas-Torres
,
F.
,
Cañizares
,
F.
, and
Perpiñán
,
O.
, “
Comparative assessment of global irradiation from a satellite estimate model (CM SAF) and on-ground measurements (SIAR): A Spanish case study
,”
Renewable Sustainable Energy Rev.
21
,
248
261
(
2013a
).
3.
Antonanzas-Torres
,
F.
,
Sanz-Garcia
,
A.
,
Martínez-de-Pisón
,
F. J.
, and
Perpiñán-Lamigueiro
,
O.
, “
Evaluation and improvement of empirical models of global solar irradiation: Case study northern Spain
,”
Renewable Energy
60
,
604
614
(
2013b
).
5.
Batlles
,
F. J.
,
Bosch
,
J. L.
,
Tovar-Pescador
,
J.
,
Martínez-Durbán
,
M.
,
Ortega
,
R.
, and
Miralles
,
I.
, “
Determination of atmospheric parameters to estimate global radiation in areas of complex topography: Generation of global irradiation map
,”
Energy Convers. Manage.
49
(
2
),
336
345
(
2008
).
6.
Bosch
,
J. L.
,
Batlles
,
F. J.
,
Zarzalejo
,
L. F.
, and
López
,
G.
, “
Solar resources estimation combining digital terrain models and satellite images techniques
,”
Renewable Energy
35
(
12
),
2853
2861
(
2010
).
7.
Corripio
,
J.
, “
Vectorial algebra algorithms for calculating terrain parameters from DEMs and solar radiation modelling in mountainous terrain
,”
Int. J. Geogr. Inf. Sci.
17
,
1
23
(
2003
).
8.
Hay
,
E.
and
Mckay
,
D. C.
, “
Estimating solar irradiance on inclined surfaces: A review and assessment of methodologies
,”
Int. J. Sol. Energy
3
,
203
240
(
1985
).
9.
Hengl
,
T.
, “
A practical guide to geostatistical mapping
,”
2009
, see http://spatial-analyst.net/book/.
10.
Hijmans
,
R. J.
and
van Etten
,
J.
, raster: Geographic data analysis and modeling,
2013
, R package version 2.1–25, see http://CRAN.R-project.org/package=raster.
11.
Pebesma
,
E. J.
, “
Multivariable geostatistics in S: The gstat package
,”
Comput. Geosci.
30
,
683
691
(
2004
).
12.
Pebesma
,
E.
and
Graeler
,
B.
, gstat: Spatial and spatio-temporal geostatistical modelling, prediction and simulation,
2013
, R package version 1.0–16, see http://CRAN.R-project.org/package=gstat.
13.
Pebesma
,
E.
,
Bivand
,
R.
,
Rowlingson
,
B.
, and
Gomez-Rubio
,
V.
, sp: Classes and methods for spatial data,
2013
, R package version 1.0–9, see http://CRAN.R-project.org/package=sp.
14.
Perez
,
R.
,
Seals
,
R.
,
Stewart
,
R.
,
Zelenka
,
A.
, and
Estrada-Cajigal
,
V.
, “
Using satellite-derived insolation data for the site/time specific simulation of solar energy systems
,”
Sol. Energy
53
(
6
),
491
495
(
1994
).
15.
Perpiñán-Lamigueiro
,
O.
, “
solaR: Solar radiation and photovoltaic systems with R
,”
J. Stat. Software
50
(
9
),
1
32
(
2012
), see http://www.jstatsoft.org/v50/i09.
16.
Perpiñán-Lamigueiro
,
O.
, Energía solar fotovoltaica,
2013
, see http://procomun.wordpress.com/documentos/libroesf/.
17.
Perpiñán-Lamigueiro
,
O.
and
Hijmans
,
R. J.
, rasterVis: Visualization methods for the raster package,
2013
, R package version 0.20-07, see http://CRAN.R-project.org/package=rasterVis.
18.
Polo
,
J.
,
Antonanzas-Torres
,
F.
,
Vindel
,
J. M.
, and
Ramirez
,
L.
, “
Sensitivity of satellite-based methods for deriving solar radiation to different choice of aerosol input and models
,”
Renewable Energy
68
,
785
792
(
2014
).
19.
Posselt
,
R.
,
Mueller
,
R. W.
,
Stöckli
,
R.
, and
Trentmann
,
J.
, “
Remote sensing of solar surface radiation for climate monitoring—The CM SAF retrieval in international comparison
,”
Remote Sens. Environ.
118
,
186
198
(
2012
).
20.
R Development Core Team
,
R: A Language and Environment for Statistical Computing
(
R Foundation for Statistical Computing
,
Vienna, Austria
,
2013
), see http://www.R-project.org.
21.
Ruiz-Arias
,
J. A.
,
Cebecauer
,
T.
,
Tovar-Pescador
,
J.
, and
Šúri
,
M.
, “
Spatial disaggregation of satellite-derived irradiance using a high-resolution digital elevation model
,”
Sol. Energy
84
(
9
),
1644
1657
(
2010
).
22.
Ruiz-Arias
,
J. A.
,
Tovar-Pescador
,
J.
,
Pozo-Vázquez
,
D.
, and
Alsamamra
,
H.
, “
A comparative study of DEM-based models to estimate solar radiation on mountainous terrains
,”
Int. J. Geogr. Inf. Sci.
23
(
8
),
1049
1076
(
2009
).
23.
Schulz
,
J.
,
Albert
,
P.
,
Behr
,
H.-D.
,
Caprion
,
D.
,
Deneke
,
H.
,
Dewitte
,
S.
,
Dürr
,
B.
,
Fuchs
,
P.
,
Gratzki
,
A.
,
Hechler
,
P.
,
Hollmann
,
R.
,
Johnston
,
S.
,
Karlsson
,
K.-G.
,
Manninen
,
T.
,
Müller
,
R.
,
Reuter
,
M.
,
Riihelä
,
A.
,
Roebeling
,
R.
,
Selbach
,
N.
,
Tetzlaff
,
A.
,
Thomas
,
W.
,
Werscheck
,
M.
,
Wolters
,
E.
, and
Zelenka
,
A.
, “
Operational climate monitoring from space: The EUMETSAT satellite application facility on climate monitoring (CM-SAF)
,”
Atmos. Chem. Phys.
9
(
5
),
1687
1709
(
2009
).
24.
Šúri
,
M.
and
Hofierka
,
J.
, “
A new GIS-based solar radiation model and its application for photovoltaic assessments
,”
Trans. GIS
8
(
2
),
175
190
(
2004
).
25.
Trentmann
,
J.
,
Träger-Chatterjee
,
C.
,
Müller
,
R.
,
Posselt
,
R.
, and
Stöckli
,
R.
, “
Meteosat (MVIRI) solar surface irradiance and effective cloud albedo climate data sets
,” The CM SAF validation report, Technical Report, The EUMETSAT network of satellite application facilities,
2011
.
26.
Vindel
,
J. M.
,
Polo
,
J.
, and
Antonanzas-Torres
,
F.
, “
Improving daily output of global to direct solar irradiance models with ground measurements
,”
J. Renewable Sustainable Energy
5
,
063123
(
2013
).
You do not currently have access to this content.