skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Assessment of bifacial photovoltaic module power rating methodologies–inside and out

Abstract

One-sun power ratings for bifacial modules are currently undefined. This is partly because there is no standard definition of rear irradiance given 1000 W·m -2 on the front. Using field measurements and simulations, we evaluate multiple deployment scenarios for bifacial modules and provide details on the amount of irradiance that could be expected. A simplified case that represents a single module deployed under conditions consistent with existing one-sun irradiance standards lead to a bifacial reference condition of 1000 W·m -2 G front and 130-140 W·m -2 G rear. For fielded systems of bifacial modules, Grear magnitude and spatial uniformity will be affected by self-shade from adjacent modules, varied ground cover, and ground-clearance height. A standard measurement procedure for bifacial modules is also currently undefined. A proposed international standard is under development, which provides the motivation for this paper. Here, we compare field measurements of bifacial modules under natural illumination with proposed indoor test methods, where irradiance is only applied to one side at a time. The indoor method has multiple advantages, including controlled and repeatable irradiance and thermal environment, along with allowing the use of conventional single-sided flash test equipment. The comparison results are promising, showing that indoor and outdoormore » methods agree within 1%-2% for multiple rear-irradiance conditions and bifacial module construction. Furthermore, a comparison with single-diode theory also shows good agreement to indoor measurements, within 1%-2% for power and other current-voltage curve parameters.« less

Authors:
 [1];  [1];  [1];  [2];  [2];  [3]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  2. Univ. of Iowa, Iowa City, IA (United States)
  3. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
OSTI Identifier:
1358688
Report Number(s):
NREL/JA-5J00-67680
Journal ID: ISSN 2156-3381
Grant/Contract Number:  
AC36-08GO28308
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
IEEE Journal of Photovoltaics
Additional Journal Information:
Journal Volume: 7; Journal Issue: 2; Journal ID: ISSN 2156-3381
Publisher:
IEEE
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; bifacial PV; IEC 60904; photovoltaic energy simulation; photovoltaic systems; ray tracing

Citation Formats

Deline, Chris, MacAlpine, Sara, Marion, Bill, Toor, Fatima, Asgharzadeh, Amir, and Stein, Joshua S. Assessment of bifacial photovoltaic module power rating methodologies–inside and out. United States: N. p., 2017. Web. doi:10.1109/JPHOTOV.2017.2650565.
Deline, Chris, MacAlpine, Sara, Marion, Bill, Toor, Fatima, Asgharzadeh, Amir, & Stein, Joshua S. Assessment of bifacial photovoltaic module power rating methodologies–inside and out. United States. doi:10.1109/JPHOTOV.2017.2650565.
Deline, Chris, MacAlpine, Sara, Marion, Bill, Toor, Fatima, Asgharzadeh, Amir, and Stein, Joshua S. Thu . "Assessment of bifacial photovoltaic module power rating methodologies–inside and out". United States. doi:10.1109/JPHOTOV.2017.2650565. https://www.osti.gov/servlets/purl/1358688.
@article{osti_1358688,
title = {Assessment of bifacial photovoltaic module power rating methodologies–inside and out},
author = {Deline, Chris and MacAlpine, Sara and Marion, Bill and Toor, Fatima and Asgharzadeh, Amir and Stein, Joshua S.},
abstractNote = {One-sun power ratings for bifacial modules are currently undefined. This is partly because there is no standard definition of rear irradiance given 1000 W·m-2 on the front. Using field measurements and simulations, we evaluate multiple deployment scenarios for bifacial modules and provide details on the amount of irradiance that could be expected. A simplified case that represents a single module deployed under conditions consistent with existing one-sun irradiance standards lead to a bifacial reference condition of 1000 W·m-2 Gfront and 130-140 W·m-2 Grear. For fielded systems of bifacial modules, Grear magnitude and spatial uniformity will be affected by self-shade from adjacent modules, varied ground cover, and ground-clearance height. A standard measurement procedure for bifacial modules is also currently undefined. A proposed international standard is under development, which provides the motivation for this paper. Here, we compare field measurements of bifacial modules under natural illumination with proposed indoor test methods, where irradiance is only applied to one side at a time. The indoor method has multiple advantages, including controlled and repeatable irradiance and thermal environment, along with allowing the use of conventional single-sided flash test equipment. The comparison results are promising, showing that indoor and outdoor methods agree within 1%-2% for multiple rear-irradiance conditions and bifacial module construction. Furthermore, a comparison with single-diode theory also shows good agreement to indoor measurements, within 1%-2% for power and other current-voltage curve parameters.},
doi = {10.1109/JPHOTOV.2017.2650565},
journal = {IEEE Journal of Photovoltaics},
number = 2,
volume = 7,
place = {United States},
year = {Thu Jan 26 00:00:00 EST 2017},
month = {Thu Jan 26 00:00:00 EST 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 3 works
Citation information provided by
Web of Science

Save / Share: