A Sensitivity Study of the Impact of Installation Parameters and System Configuration on the Performance of Bifacial PV Arrays

Journal Article · Thu Apr 19 00:00:00 UTC 2018 · IEEE Journal of Photovoltaics

DOI: https://doi.org/10.1109/JPHOTOV.2018.2819676 · OSTI ID:1437222

Asgharzadeh, Amir ^[1]; Marion, Bill ^[2]; Deline, Chris ^[2]; Hansen, Clifford ^[3]; Stein, Joshua S. ^[3]; Toor, Fatima ^[1]

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1. Univ. of Iowa, Iowa City, IA (United States)
2. National Renewable Energy Lab. (NREL), Golden, CO (United States)
3. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

In this paper, we present the effect of installation parameters (tilt angle, height above ground, and albedo) on the bifacial gain and energy yield of three south-facing photovoltaic (PV) system configurations: a single module, a row of five modules, and five rows of five modules utilizing RADIANCE-based ray tracing model. We show that height and albedo have a direct impact on the performance of bifacial systems. However, the impact of the tilt angle is more complicated. Seasonal optimum tilt angles are dependent on parameters such as height, albedo, size of the system, weather conditions, and time of the year. For a single bifacial module installed in Albuquerque, NM, USA (35 degrees N) with a reasonable clearance (~1 m) from the ground, the seasonal optimum tilt angle is lowest (~5 degrees) for the summer solstice and highest (~65 degrees) for the winter solstice. For larger systems, seasonal optimum tilt angles are usually higher and can be up to 20 degrees greater than that for a single module system. Annual simulations also indicate that for larger fixed-tilt systems installed on a highly reflective ground (such as snow or a white roofing material with an albedo of ~81%), the optimum tilt angle is higher than the optimum angle of the smaller size systems. We also show that modules in larger scale systems generate lower energy due to horizon blocking and large shadowing area cast by the modules on the ground. For albedo of 21%, the center module in a large array generates up to 7% less energy than a single bifacial module. To validate our model, we utilize measured data from Sandia National Laboratories' fixed-tilt bifacial PV testbed and compare it with our simulations.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S), SunShot National Laboratory Multiyear Partnership (SuNLaMP); USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Program (EE-2A)
• Grant/Contract Number: AC04-94AL85000; AC36-08GO28308
• OSTI ID: 1437222
• Report Number(s): NREL/JA--5K00-71518; SAND--2018-12213J
• Journal Information: IEEE Journal of Photovoltaics, Journal Name: IEEE Journal of Photovoltaics Journal Issue: 3 Vol. 8; ISSN 2156-3381
• Publisher: IEEECopyright Statement
• Country of Publication: United States
• Language: English