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Shows curves of spectral senstivity as a function of irradiation | Shows curves of spectral senstivity as a function of irradiation | ||
-- | --[http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6V51-3YN9DSN-3-1&_cdi=5773&_user=1025668&_pii=092702489400165O&_orig=search&_coverDate=01%2F31%2F1995&_sk=999639998&view=c&wchp=dGLzVzz-zSkzV&_valck=1&md5=6352c4cb62f92b56f082585b3b521aa4&ie=/sdarticle.pdf 1. Rüther R, Livingstone J. Seasonal variations in amorphous silicon solar module outputs and thin film characteristics. Solar Energy Materials and Solar Cells 1995 Jan;36(1):29-43.] | ||
Outdoors testing of A:Si generally leads to better efficiency in summer, worse in winter | |||
Attributed to thermal annealing and seasonal spectral variations | |||
Conclusion of this paper is that spectral effects are dominating | |||
first cells utilized indoors in calculators | |||
power efficiency from 71% in winter to 83% in summer | |||
bandgap from 360-780 | |||
Crystal silicon is better in the winter | |||
therefore, the seasonal variatoin is likely due to the seasonal changes in spectrum, not annealing. Does not really support this with numbers |
Revision as of 15:54, 7 September 2010
Back to Main Page: Effects of snow on photovoltaic performance
Spectral effects on amorphous PV cells
--Effect of atmospheric parameters on the silicon solar cells performance, M. Chegaar, P. Mialhe Spectral effects simulated for Algeirs
effects in short-circuit current due to turbidity, decrease of: 4.41%, 4.7%, 7.34% for mono multi and amorphous. Turbidity decreases UV radiaiton
Increasing water vapour leads to decrease of 4.57%,4.4%, o.2% for same
Efficiency increase with air mass for crystalline, decrease for amorphous
--[1. Rüther R, Kleiss G, Reiche K. Spectral effects on amorphous silicon solar module fill factors. Solar Energy Materials and Solar Cells 2002 Feb;71(3):375-385.]
amorphous silicon is more efficient in the summer
crystalline more efficient in winter
A:Si matches very well with indoor illumination spectra, they are more efficient indoors
Spectral mismatch factor: ratio between Isc rated and Isc extrapolated to 1000W/m2
Does not neccesarily hold true for a:Si cells: "However, in amorphous silicon solar cells, the proposition of the non-dependence of sðlÞ on the operating voltage does not hold. It is known that in p-i-n structures a typical blue-dispersion of the spectral response occurs for higher bias voltages [14]. Since the field-driven transport is the dominant mechanism with respect to diffusion, and since the electrical field is extended over practically the whole cell, the generation profile inside the cell produces a feedback on the internal quantum efficiency. In a-Si cell modelling, one takes advantage of this effect by application of the DICE method [12,15,16] to yield for a spatially resolved description of the field distribution inside the cell."
FF is the ratio between Imp and Isc
Used a filtered pyranometer to find "Red" and "Blue" spectra
Plots of FF vs Isc,shows much scatter in the central area of Isc.
Attrubited to the spectral effect, blue increasing FF, red to decrease it
Shows curves of spectral senstivity as a function of irradiation
Outdoors testing of A:Si generally leads to better efficiency in summer, worse in winter
Attributed to thermal annealing and seasonal spectral variations
Conclusion of this paper is that spectral effects are dominating
first cells utilized indoors in calculators
power efficiency from 71% in winter to 83% in summer
bandgap from 360-780
Crystal silicon is better in the winter
therefore, the seasonal variatoin is likely due to the seasonal changes in spectrum, not annealing. Does not really support this with numbers