Tropical climates (such as in Singapore) are characterised by fast-changing irradiance conditions due to high variations in cloud coverage. Different photovoltaic (PV) technologies possibly react differently to these variations of irradiance conditions, which in turn will also influence the module performance. In this study, a novel method is introduced to systematically investigate the fluctuating irradiance and its influence on module performance. Taking the Adnot clear-sky irradiance model as reference, the fluctuating irradiance is separated into high and low irradiance levels using the Typical Meteorological Day (TMD) irradiance values of 2011. These two irradiance groups are then analysed individually for the impact of the fluctuation frequency (defined via the number of minutes of constant irradiance) on the following module parameters: short-circuit current, module temperature and efficiency. The distribution of fluctuating irradiance over a whole year in Singapore and its impact on 5 different module technologies (monocrystalline Si, hetero-junction Si wafer, a-Si single junction, a-Si double junction and micromorph Si) are presented. The results show that the efficiency of wafer-based Si modules is not much influenced by the fast irradiance changes and dominated by the temperature effect at high irradiance. In contrast, Si-based thin-film technologies are stronger impacted by the fluctuations. Amorphous Si technologies show higher efficiencies at low irradiances, while micromorph Si modules react similar to monocrystalline Si at high irradiances, however with a slight drop in efficiency at low irradiances. This study gives valuable insights into the PV module response to varying irradiance.
[1]
Serm Janjai,et al.
Semi-empirical models for the estimation of clear sky solar global and direct normal irradiances in the tropics
,
2011
.
[2]
I. Reda,et al.
Solar Position Algorithm for Solar Radiation Applications (Revised)
,
2008
.
[3]
Benjamin Y. H. Liu,et al.
The interrelationship and characteristic distribution of direct, diffuse and total solar radiation
,
1960
.
[4]
R. Belmans,et al.
Fluctuations in instantaneous clearness index: Analysis and statistics
,
2007
.
[5]
Joshua S. Stein,et al.
IMPROVEMENT AND VALIDATION OF A TRANSIENT MODEL TO PREDICT PHOTOVOLTAIC MODULE TEMPERATURE.
,
2012
.
[6]
Avraham I. Kudish,et al.
Inter-comparison of different models for estimating clear sky solar global radiation for the Negev region of Israel
,
2007
.
[7]
G. Bunea,et al.
Low Light Performance of Mono-Crystalline Silicon Solar Cells
,
2006,
2006 IEEE 4th World Conference on Photovoltaic Energy Conference.
[8]
Kenji Yamamoto,et al.
Spectral Effects of a Single-Junction Amorphous Silicon Solar Cell on Outdoor Performance
,
2004
.
[9]
P. Jirutitijaroen,et al.
Hourly solar irradiance time series forecasting using cloud cover index
,
2012
.
[10]
A. D. Jones,et al.
A thermal model for photovoltaic systems
,
2001
.