Spectral shift

[n.solar]

Hello!

I am a solar energy prediction analyst working for an EPC company in the United States, and I’m wondering if PVsyst is going to take the effects of Spectrum into consideration? I know there was a post about a month ago on the subject but there still have been no answers to it. There have been multiple studies published that show irrefutable facts that Spectrum has an effect on many different Photovoltaic Systems including mono crystalline Silicon and Cadmium Telluride.

It is undeniable that modules will not perform in outdoor spectrums as they do when reacting to the flash testing under static spectral irradiance defined in ASTM G173. Also there is an obvious shift in the generation of energy for different types of modules in different locations, and studies have been done to show that this is true (listed below).

It is also known that CdTe modules are more affected by precipitable water content, and that c-Si modules are affected by air mass. And since so many different models have been suggested to account for these shifts in performance, I am wondering if this type of analysis could be taken into consideration.

Below are a few papers discussing Spectrum.

Thank you!

M. Lee, L.Ngan, W. Hayes, A. Panchula. “Understanding next generation cadmium telluride photovoltaic performance due to spectrum,” 42nd IEEE Photovoltaic Specialists Conference, 2015, (Submitted).

B. Duck, C. Fell. “Comparison of methods for estimating the impact of spectrum on PV output,” 42nd IEEE Photovoltaic Specialists Conference, 2015, (Submitted).

D. Dirnberger, B. Müller, and C. Reise, “On the uncertainty of energetic impact on the yield of different PV technologies due to varying spectral irradiation,” Solar Energy, vol. 111, pp. 82-96, 2015.

M. Schweiger, W. Herrmann, U. Rau. “Comparison of energy yield data of fifteen pv module technologies operating in five different climates,” 42nd IEEE Photovoltaic Specialists Conference, 2015, (Submitted).

B. Bora, O.S. Sastry, A. Kumar, M. Bangar, R. Dahiya. “Performance modeling of three PV module technologies based on clearness index and air-mass using contour map,” 42nd IEEE Photovoltaic Specialists

Conference, 2015, (Submitted).

R. Darbali-Zamora, C. Gómez-Mendex, H. Li, E. Ortiz-Rivera, J. Wang. “Solar irradiance prediction model based on a statistical approach for microgrid application,” 42nd IEEE Photovoltaic Specialists Conference,

2015, (Submitted).

L. Mutiara, K. Pegels, A. Reinders. “Evaluation of spectrally distributed irradiance in the Netherlands regarding the energy performance of various PV technologies,” 42nd IEEE Photovoltaic Specialists Conference, 2015, (Submitted).

K. Klise, C. Hansen, J. Stein. “Dependence on geographic location of air mass modifiers for photovoltaic module performance models,” 42nd IEEE Photovoltaic Specialists Conference, 2015, (Submitted).

A. Virtuani, A. Skoczek, D. Strepparava. “Modeling the performance of amorphous silicon photovoltaic modules for different geographical locations in North-America,” 42nd IEEE Photovoltaic Specialists Conference, 2015, (Submitted).

Y. Kumar Singh, B. Bora, R. Singh, S. Agaria, V. Sharma, A. Kumar, O.S. Sastry. “Effect of spectrum and temperature on seasonal performance of CdTe technology in composite climate of India,” 42nd IEEE Photovoltaic Specialists Conference, 2015, (Submitted).

B. Marion, M. Deceglie, T. Silverman. “Analysis of measured photovoltaic module performance for Florida, Oregon, and Colorado locations,” Solar Energy, vol. 110, pp. 736-744, 2014.

D. Dirnberger, G. Blackburn, B. Müller, and C. Reise, “On the impact of solar spectral irradiance on the yield of different PV technologies,” Solar Energy Materials and Solar Cells, vol. 132, pp. 431-442, 2014.

B. Marion. “Influence of atmospheric variations on photovoltaic performance and modeling their effects for days with clear skies,” 39th IEEE Photovoltaic Specialists Conference, 2015.

G. Litjens. “Investigation of spectral effects on photovoltaic technologies by modelling the solar spectral distribution.” (2013)

[André Mermoud]

As you say, there are many models proposed for different technologies.

These models usually require meteorological information (like precipitable water contents, or humidity), which are not yet implemented in the import and treatment of meteo data of PVsyst in the present time.

We intend to do so in a rather near future, but we have still other priorities in the present time.

NB: The instantaneous shifts may be important in some situations, but the annual balances are usually rather low. Except perhaps for specific technologies like CdTe.

[S.Faulkner]

My understanding is that clouds cause a blue-shift which has a small effect on c-Si modules, but low sun causes a red-shift that has an opposite effect. And therefore these balance to some extent. Is that right?

Some consideration of these would be nice to have, but nowhere as nice to have as sub-hourly processing, in my humble opinion.