Bifacial PV System Mismatch Loss Estimation & Parameterization

Conference · Thu Sep 26 00:00:00 EDT 2019

OSTI ID:1569210

Deline, Christopher A ^[1]; Ayala Pelaez, Silvana ^[1]; MacAlpine, Sara ^[2]; Olalla, Carlos ^[3]

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1. National Renewable Energy Laboratory (NREL), Golden, CO (United States)
2. Juwi Solar Americas, Boulder, CO USA
3. Rovira i Virgili University, Tarragona, Spain

Non-uniform irradiance on the rear-side of bifacial PV systems can cause additional mismatch loss which may not be appropriately captured in PV energy production estimates and software. We have evaluated several rooftop mounted systems over high albedo reflective roofs. Mismatch losses of up to 2% annual loss for very close-mounted (0.15 m) rooftop systems were found, but losses for high ground-clearance rooftop systems were lower (<0.5%). A simplified empirical relationship was found that links the spatial variation of irradiance (specifically the mean absolute difference of irradiance) to the resulting mismatch loss factor, with a R2 fit better than 0.985. This approximate relationship has been validated by experiments on mismatched PV modules, and provides a basis for fast estimation of bifacial mismatch loss factors for use in hourly PV performance simulations such as PVSyst or SAM.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 1569210
• Report Number(s): NREL/PR-5K00-74885
• Conference Information: Presented at the 36th European PV Solar Energy Conference and Exhibition (EU PVSEC), 9-13 September 2019, Marseille, France
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
47 OTHER INSTRUMENTATION
bifacial PV system
irradiance distribution
photovoltaic
power output
PV
solar