28 June 2015 to 3 July 2015
Africa/Johannesburg timezone
SAIP2015 Proceeding published on 17 July 2016

Determining the effect of the solar cell band gap on power yield in southern African irradiance conditions

2 Jul 2015, 09:40
20m
Oral Presentation Track F - Applied Physics Applied

Speaker

Mr Graham Webber (University of Johannesburg)

Apply to be<br> considered for a student <br> &nbsp; award (Yes / No)?

Yes

Abstract content <br> &nbsp; (Max 300 words)<br><a href="http://events.saip.org.za/getFile.py/access?resId=0&materialId=0&confId=34" target="_blank">Formatting &<br>Special chars</a>

Solar panel yield is determined both by the local available solar irradiance and the detector characteristics. The Shockley-Queisser limit is the theoretical limit of maximum efficiency of any single junction solar cell. It is based on the maximum possible yield for the band gap of the junction in question and not on any practical or manufacturing limits. To a first approximation this limit is calculated for the irradiance at the top of the atmosphere. A more accurate calculation requires considerations of the solar ray attenuation at the specific site of measurement. The contributions to the irradiance are not proportionally the same on the surface of the earth as at the top of the atmosphere, as different wavelengths of incident light are scattered and absorbed differently. As such the optimal band gap on the surface of the Earth will slightly differ from that obtained from the first order approximation. Due to the variability of atmospheric conditions with time and geographical position, this optimal band gap will also vary with time, location and orientation. This paper calculates the optimum band gap for site specific parameters, such as latitude, altitude and aerosol types, descriptive of southern African sites identified for solar power generation. The paper highlights the key factors that influence the band gap optimisation, which would assist in the research and development of more efficient solar cells, under southern African atmospheric conditions and allow for more accurate predictions to be made for local solar power yield.

Main supervisor (name and email)<br>and his / her institution

Hartmut Winkler hwinkler@uj.ac.za University of Johannesburg

Level for award<br>&nbsp;(Hons, MSc, <br> &nbsp; PhD, N/A)?

MSc

Please indicate whether<br>this abstract may be<br>published online<br>(Yes / No)

Yes

Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?

Yes

Primary author

Mr Graham Webber (University of Johannesburg)

Co-author

Prof. Hartmut Winkler (Dept. Physics, University of Johannesburg)

Presentation Materials