Improved outdoor monitoring of photovoltaic modules

The Centre for Renewable Energy Systems Technology (CREST) has been operating an outdoor measurement facility for testing photovoltaic (PV) modules since 1998. The facility is used to continuously measure the performance of a range of commercial and prototype modules, by scanning full I-V characteristics every ten minutes with synchronous measurements of ambient and module temperatures and broadband and spectral irradiance. The trend for increasingly high power PV modules and increased demand for channels has precipitated the next stage of development for the CREST system. A number of lessons have been learned from the past system which are indicated in this paper with a thorough system analysis, along with a description of the standard measurement cycle currently in operation. Then follows a full technical description of the new system, including the hardware design and software development.