As emerging thin-film PV technologies continue to penetrate the market and the number of utility scale installations
substantially increase, detailed understanding of the performance of the various PV technologies becomes more
important. An accurate database for each technology is essential for precise project planning, energy yield prediction and
project financing. However recent publications showed that it is very difficult to get accurate and reliable performance
data of theses technologies.
This paper evaluates previously reported claims the amorphous silicon based PV modules have a higher annual energy
yield compared to crystalline silicon modules relative to their rated performance. In order to acquire a detailed
understanding of this effect, outdoor module tests were performed at GE Global Research Center in Munich. In this
study we examine closely two of the five reported factors that contribute to enhanced energy yield of amorphous silicon
modules. We find evidence to support each of these factors and evaluate their relative significance. We discuss aspects
for improvement in how PV modules are sold and identify areas for further study further study.