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Title: Methodology to predict annual yield losses and gains caused by solar module design and materials under field exposure

Journal Article · · Solar Energy Materials and Solar Cells
 [1];  [2];  [1]
  1. Australian National Univ., Canberra (Australia)
  2. National Renewable Energy Lab. (NREL), Golden, CO (United States)

Solar cells and modules are usually optimized separately under standard test conditions (STC). However, the actual performance under field exposure depends on module design, installation and environmental conditions. This work therefore presents a methodology to predict the annual yield of crystalline silicon solar modules for varying module configurations and environments using a time step simulation approach. We define and quantify 12 effects that affect the annual module performance, starting with solar cells in air under STC to a complete module under realistic conditions. We consider the interaction of optical, thermal and electrical effects in the module and combine it with an angular, spectral and time resolved light source. The model enables understanding the impact of the module environment, such as regions with high wind speeds or high diffuse light, on the annual output of a particular module type. We validate our model with measured power and temperature data for crystalline silicon heterojunction solar cell modules and find an agreement of the annual yield within 0.7%. We quantify the annual gains and losses for this module and identify that major losses are caused by elevated operating temperatures (2.3%) and reflection losses at the front glass (2.6%). Critically, the coupling gains at the cell surface increase significantly by 1.5% when considering angular light irradiance compared to normal incidence. To conclude, we apply our Cell-to-Module-Yield method to a 72-cell mono-crystalline PERC module, where the main annual yield losses are caused by reflection at the front glass and ohmic losses in the connector ribbons.

Research Organization:
National Renewable Energy Laboratory (NREL), Golden, CO (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
Grant/Contract Number:
AC36-08GO28308
OSTI ID:
1570190
Report Number(s):
NREL/JA-5K00-75077
Journal Information:
Solar Energy Materials and Solar Cells, Vol. 202, Issue C; ISSN 0927-0248
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 8 works
Citation information provided by
Web of Science