Category EuroSun2008-13

Benchmarking

Benchmarking is the largest activity within the MESoR project. The aim of the benchmarking exercise is to establish a coherent set of benchmarking rules and reference data sets to enable a transparent and comparable evaluation of the different solar radiation data sources. The rules are developed in conjunction with the IEA Task 36 on “Solar Resource Management” of the Solar Heating and Cooling Implementing Agreement and shall serve as a standard for benchmarking to make results comparable.

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Analysed databases and integrated systems

Each of the databases analysed here is integrated within a system (software setup) that provides additional tools for search, query, maps display, and calculation of derived parameters. PVGIS (the European section), includes solar radiation database developed by combination of solar radiation model and interpolated ground observations. The datasets Satel-Light and HelioClim-2 (accessible through the SoDa web portal) are built from Meteosat and MSG satellite images, respectively. NASA SSE release 6 (accessible also through RETScreen software) combines results from ISCCP

satellite project with NCAR reanalysis products. Primary data incorporated inMeteonorm version

6.1 and ESRA are developed by interpolation of ground observed data with support of satellite images (MSG and SRB, respectively)...

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Own measured data

A multicomponent solar thermal system was installed in Bishkek to preheat water for a district heating net in the context of a joint research project of Kassel University (Germany) and Kyrgyz State Technical University in Bishkek (Kyrgyzstan). For detailed investigations different parameters including solar radiation are measured since autumn 2004 with very accurate sensors every 15 seconds to generate one-minute mean values. Solar radiation is measured with pyranometer Kipp&Zonen CM11 with an accuracy of 1.5% of the measured values. For some periods, however, the measurement data is missing for different reasons (e. g. technical problems with the sensor power supply unit or no power supply at all)...

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Linke’s Turbidity Factor Applied to Worldwide Global. Horizontal Irradiance Measurements

Frank Bason

SolData Instruments, Linabakken 13, DK-8600 Silkeborg, Denmark
Corresponding Author, soldata@soldata. dk

Abstract

The data collection phase of the Danish Galathea III Expedition was conducted from August 2006 until April 2007 [1]. During this period the research vessel Vmdderen undertook a round the world voyage of nearly 100.000 kilometers while acting as a platform for scientific research in a range of disciplines. The researchers and instruments aboard the ship collected data from many locations around the world from 66.90 N to 67.50 S latitude...

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Data base and compare

1.1. Information of stations

The global solar radiation and sunshine duration data during the period from 1994 to 2003 reported in this paper were provided by the China Meteorological Administration (CMA). Professor Tien Shengyuan has divided climatic zone of China into eight large-scale climatic zones, and he also has advanced the representative city for every climatic zone in the year of 1989. The information of these cities is as follows [3]

Table. 1. The information of representative stations

number

station

latitude(°N)

longitude (°E)

altitude (m)

data duration

1

Harbin

45°45’

126°46’

142.3

1994-2003

2

Lanzhou

36°03’

103°53’

1517.2

1994-2003

3

Beijing

39°48’

116°28’

31.3

1994-2003

4

Wuhan

30°37’

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Avoiding boundary uncertainties under prediction

By convolution, the length of the scaled and translated wavelet functions in the DWT is distinct from the signal length, which can lead to additional convolution uncertainties on the boundaries of the signal as stated in [19]. The authors of paper [9], as well as a large number of references which using the orthogonal DWT as auxiliary tool to obtain performance improvement of Time Series Prediction (TSP) models, do not consider that its obtained performance may not hold for the operation of the prediction model. The documented uncertainty may increase during the application of the model to predict unknown future values in real or actual time...

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Study Area

The region of the study is the area of Andalusia, in the southern part of Iberian Peninsula (Figure 1), covering around 87.000 km2. The region is located in the transition zone from middle latitudes to subtropical climates (latitudes 35° 30′ to 38° 30′ N and longitudes 7° 30′ to 1° 30 W), with the Atlantic Ocean and the Mediterranean region in the southern bound.

image012

Fig.1. Localization of the study area

2.1. Dataset

The experimental dataset used in the study includes four year (2003-2006) of daily global radiation in the horizontal surface values, measured at 166 meteorological stations along the study region.

Подпись: Fig.2. Training and validation stations used in the study

The stations are owned and maintained by the Andalusia Regional Government, and are part of the Agricultural and Environmental monitoring network...

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Direct Normal Irradiance from Satellite VIS Images

The calculation of the direct normal irradiance is performed in different steps. In a first step cloud information is derived from the satellite measurements using an enhanced version of the Heliosat method [1]. As a measure of cloudiness a dimensionless clear sky index k* is derived. Using a clear sky model the global irradiance is immediately related to the clear sky index, while our new beam fraction model allows for calculating the DNI. Fig. 1 represents the necessary process steps, which are described in this section.

image091

Fig. 1: Significant process steps of the Heliosat method.

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