Site data analysis of CPV plants

Abstract

Since 2007 SolFocus has installed close to 2 MW of concentrated photovoltaic (CPV) power plants at multiple sites around the world. These installations have proved essential for assessing the value and variability of energy generation and performance ratio, as well as how accurately SolFocus is able to model and predict the product performance of its sites. This paper shares the data and results of performance ratio and energy production analyses at 4 of these sites, ISFOC in Puertollano (Spain), Palo Alto Water in California, APS Star Center in Arizona, and EDF in Alto Monte (Italy). The analysis was performed for both the SF-1000S and SF-1100S, SolFocus first and second generation CPV systems, and leveraged over 24 months of site data, including energy output, solar irradiation, temperature, and maintenance activities. Results show that the SolFocus products exhibit consistently high performance ratios (PR) in the field, ranging from 87% to 91%, as measured at the inverter under clean conditions. In addition, the tight distribution of performance ratios between the multiple arrays demonstrates a highly consistent product performance and characteristics. The measured performance ratios are consistent with the modeled values as calculated by the SolFocus proprietary energy calculator. Furthermore, the energy produced under normal conditions at all 4 sites match closely the modeled energy at these sites, validating SolFocus's ability to make accurate energy production projections.