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Title: All About PID - Testing and Avoidance in the Field

Abstract

Potential-induced degradation can cause significant power loss in modules if the appropriate precautions are not taken. In the first part of a new series in PV Tech Power on module failure, Peter Hacke and Steve Johnston assess the current state-of-the-art in detecting, avoiding and mitigating the worst effects of PID.

Authors:
;
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:
1326899
Report Number(s):
NREL/JA-5J00-66799
DOE Contract Number:
AC36-08GO28308
Resource Type:
Journal Article
Resource Relation:
Journal Name: Photovoltaics International; Journal Volume: 33
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; PID; potential-induced degradation test; IEC 62804-1

Citation Formats

Hacke, Peter, and Johnston, Steve. All About PID - Testing and Avoidance in the Field. United States: N. p., 2016. Web.
Hacke, Peter, & Johnston, Steve. All About PID - Testing and Avoidance in the Field. United States.
Hacke, Peter, and Johnston, Steve. 2016. "All About PID - Testing and Avoidance in the Field". United States. doi:.
@article{osti_1326899,
title = {All About PID - Testing and Avoidance in the Field},
author = {Hacke, Peter and Johnston, Steve},
abstractNote = {Potential-induced degradation can cause significant power loss in modules if the appropriate precautions are not taken. In the first part of a new series in PV Tech Power on module failure, Peter Hacke and Steve Johnston assess the current state-of-the-art in detecting, avoiding and mitigating the worst effects of PID.},
doi = {},
journal = {Photovoltaics International},
number = ,
volume = 33,
place = {United States},
year = 2016,
month = 9
}
  • Amphipods (Eohaustorius estuarius) were placed in two-chamber containers with different combinations of three contaminated sediments and a control sediment, and their distribution was determined after 2 or 3 d. Amphipods avoided the sediment with the highest PAH contamination and one of two sediments with moderate PAH concentrations. In the moderately contaminated sediment avoided by amphipods, the (avoidance) response was more sensitive than mortality as a biological indicator of unacceptable sediment contamination. The avoidance response in this case likely represents an early indication of potential mortality from sediment exposure. Population levels of amphipods in moderately to heavily PAH-contaminated sediments may bemore » influenced by a combination of avoidance behavior and toxicity/lethality.« less
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  • Purpose: Breast cancer patients with bilateral implant reconstructions who require postmastectomy radiotherapy can pose unique treatment planning challenges. The use of VMAT may provide advantages over conventional tangent or multi-beam IMRT techniques. Moreover, daily setup uncertainly of the arm position, however, could have significant impact on accurate dose delivery. This study compares the plan qualities between non-AA and AA VMAT techniques. Methods: Three breast cancer patients receiving left chest wall and regional nodal irradiation with bilateral implant reconstructions were studied. PTV included chest wall and IMNs (PTV-CW), and supraclavicular and axillary lymph nodes (PTV-SCV). For each patient, one non-AA VMATmore » plan (VMAT-S) with 4 partial arcs encompassing the ipsilateral arm and three AA VMAT plans where no arcs were entering or existing through the ipsilateral arm were generated. VMAT-AA1 uses 2 arcs for PTV-CW and 2 arcs for PTV-SCV. VMAT-AA2 used two static fields for PTV-SCV with 2 arcs for PTV-CW. VMAT-AA3 used 2 narrow arcs for PTV-CW and 2 long arcs for all PTVs. Prescription dose (PD) was 50 Gy (25 fractions). All plans were normalized to have 95% of PD to 95 % of PTV. PTV dose inhomogeneity and dose to the heart, left lung, right thyroid dose and left humerus were evaluated. Results: For VMAT-S, VMAT-AA1, VMAT-AA2 and VMAT-AA3, respectively, the average and standard deviation (in Gy unless specified otherwise) of PTV D05 are 54.7±0.9, 55.9±0.4, 56.7±0.7 and 55.7±0.4; mean Heart dose: 7.1±0.7, 7.2±0.8, 7.3±0.9 and 6.9±1.0; left lung V20Gy (in %): 28.1±1.0, 28.8+2.2, 32.2±4.1 and 27.8±2.0; mean right thyroid dose: 8.1±0.6, 5.1±2.1, 2.1±0.4 and 5.0±2.0; mean left humerus dose: 20.0±4.4,15.6±4.4, 15.2±8.2 and 15.3±4.6. Conclusion: AA VMAT can produce acceptable clinical plans while eliminating dosimetric impact related to arm setup uncertainty. These data require validation in larger planning studies prior to routine clinical implantation.« less