Operation and Performance Assessment of Grid-Connected PV Systems in Operation in Maui, Hawaii

Numerous assessments have been conducted around the world to characterize using the performance ratio (PR) the energy production (energy rating) of different PV technologies and manufacturers. Experimental results vary between locations and the single PR criterion is not enough to understand the performance variability. Using present modelling tools, energy rating is possible but there are still uncertainties requiring additional data collection and analysis especially in terms of the effects of spectrum, angle-of-incidence and degradation. The Hawaii Islands have high solar resource, spectrum rich in short wavelength and a hot and humid environment expected to rise degradation rate. Testing in Hawaii provides an ideal environment to support research on PV technologies. A PV test platform, commissioned on the island of Maui in February 2016, tests side by side 15 grid-connected PV systems. A new energy rating analysis is proposed where PR is separated into current (IP) and voltage (VN) performances. These additional criteria help understand the performance differences between PV modules and locations which will lead to better select the PV technology to certain environment. This approach also helps identify the parameters of operation to dissociate the impacts of the environmental and operating conditions (soiling, shading). At the Maui test platform, the yearly average PR is estimated between 87% to 98% depending on the PV systems, with 2 thin films (CIGS, CdTe) over performing the standard and high efficient crystalline modules. IP is evaluated between 95% and 100% for most PV manufacturers except for one low (91%, CIGS) and one high (104%, CdTe) performer. VN ranges between 87% and 98%, the CIGS exhibiting high voltage performance compared to the other technologies.