Keeping tabs on PV module efficiency

When talking about the efficiency of PV modules, there are seemingly infinite numbers to talk about.  First, there is the different types of modules, like c-Si, a-Si, CdTe, CIGS, CPV, on and on and on.  Then, there is the different conditions under which efficiency is measured, like IEC 60904-3, ASTM G-173-03, IEC CSTC, on and on and on.  It easy to understand how someone even working in solar would very easily get confused by all of these numbers, results, conditions and technologies.

But there is one document that has taken the lead in organizing and presenting all of these different values in an attempt to present results on equal grounds.  This is the perpetually published Solar Cell efficiency tables (currently on Version 41) by Martin A. Greene et al, which was last released in late 2012.  About one to two times a year, a new version is published and all in the world of PV efficiency is clear, if even for a moment.  I urge anyone with interest in the topic of PV technology and modules to review this document in its most current release and get a real sense for where efficiency currently resides in the PV world.