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Research Staff

A group of 15 men and women standing next to solar panels outside of an NREL research laboratory.

Experienced scientists, engineers, and technicians lend their expertise as members of the Photovoltaic Reliability Group at NREL.

Our group is founded on the expertise and interaction of talented individuals.

Members of the group have diverse backgrounds in physics, engineering, chemistry, building design, remote sensing, electrical design, and materials science.

Photo of Nick Bosco.

Infrared image of Nick Bosco

Nick Bosco, PhD, Senior Scientist

OTF/204, 303-384-6337

Task Focus:

Failure Analysis and Accelerated Testing

Specializes in:

Infrared imaging and other diagnostic techniques; analysis and development of accelerated tests for mechanical fatigue

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Photo of Michael Decegliee.

Michael Deceglie

Michael Deceglie, PhD, Post Doc

OTF/203, 303-384-6104

Task Focus:

Understanding performance of and metastabilities in thin-film modules

Specializes in:

Device physics. Indoor and outdoor module performance measurements.

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Photo of Chris Deline.

Chris Deline

Chris Deline, PhD, Engineer

OTF/209-02, 303-384-6359

Task Focus:

PV Module and System Performance

Specializes in:

Modeling and analysis of modules under shaded or partially degraded conditions, with emphasis on DC-DC converters and microinverters.

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Photo of Steve Glick.

Steve worked with a team of researchers to set up the 5-chamber PECVD system in SERF/W213.

Steve Glick, Scientist

OTF/104, 303-384-6650

Task Focus:

Electroluminescent, infrared, and visual imaging of PV modules

Specializes in:

Materials science of photovoltaic module materials.

Known for:

Material deposition of thin-film moisture barriers; alternative encapsulant formulations development; reliability and encapsulant performance studies related to photothermal degradation.

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Photo of Peter Hacke.

Peter Hacke, PhD

Peter Hacke, PhD, Senior Scientist

OTF/206, 303-384-6668

Task Focus:

Accelerated Testing of PV Modules

Specializes in:

Failure analysis and use of accelerated testing to make long-term predictions about module performance.

Known for:

Work on potential-induced degradation of crystalline silicon modules.

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Photo of Dirk Jordan.

Dirk Jordan, PhD

Dirk Jordan, PhD, Senior Reliability Engineer

OTF/203, 303-384-6762

Task Focus:

Evaluation of Outdoor Module Performance Data

Specializes in:

Analysis of module performance data to quantify module degradation rates.

Known for:

Statistical analysis of reported degradation rates of PV modules.

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Photo of Mike Kempe.

Mike places samples in an environmental chamber to determine the effect of humidity on polymer adhesion.

Mike Kempe, PhD, Scientist

SERF E-100-50, 303-384-6325

Task Focus:

PV Module Packaging R&D

Specializes in:

Coordinating and performing materials durability testing.

Known for:

Interest in the role of polymer chemistry and physics in module degradation; lap-shear, water-vapor transmission, and water-solubility testing of encapsulants and edge seals; using results in finite element analysis to determine length of time it takes for water to enter a module.

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Photo of Sarah Kurtz.

Sarah Kurtz

Sarah Kurtz, PhD, Principal Scientist, Reliability Group Manager

SERF/W107, 303-384-6475

Task Focus:

PV Reliability Project Management and Standards Development, especially for CPV.

Known for:

Developing multijunction concentrator cells and supporting the CPV industry.

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Photo of Bill Marion.

Bill works on systems performance modeling, shown on the computer screen behind him.

Bill Marion, Principal Scientist

OTF/202-01, 303-384-6793

Task Focus:

Module/System Technology Testing and Validation

Specializes in:

Solar Radiation Resource Information and PV module and system performance modeling.

Known for:

Advanced capability in PV modeling; IV curve translations.

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Photo of David Miller.

David in front of environmental chamber used to perform accelerated aging on reflective (shown) and transmissive components of traditional and concentrating solar equipment.

David Miller, PhD, Scientist

OTF/108-05, 303-384-7855

Task Focus:

Accelerated Testing and Failure Analysis of Photovoltaic Components and Modules

Specializes in:

Materials characterization for reliability and lifetime assessment. Current activities include: "optical side" of CPV, including materials for encapsulation and optical components (lenses); encapsulation materials for conventional flat-plate PV, including crystalline-Si and thin-film technologies; reliability of thin-film PV, including transparent conductive oxide and active device layers.

Known for:

Characterization and reliability assessment of micro- and nanomaterials. Past studies include: mechanical robustness of nanoscale thick films, deposited by atomic layer deposition (ALD) and molecular layer deposition (MLD), for chemical permeation barrier applications; galvanic corrosion in Si/metal systems for microelectromechanical systems (MEMS) applications; mechanical properties of nanowire materials; thermo-mechanical reliability of Au/Si system for optical MEMS applications. Background in mechanical engineering with emphasis on materials science.

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Photo of Matthew Muller.

Matt is standing next to PV shingles on a roof in the Outdoor Test Facility (OTF) array field.

Matthew Muller, Engineer

OTF/209-01, 303-384-6164

Task Focus:

PV Module/Array Performance Testing

Specializes in:

Testing building-integrated PV; implementing a high-accuracy tracker for testing CPV modules; data acquisition and analysis; characterization of operating temperatures.

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Photo of Greg Perrin.

Greg Perrin

Greg Perrin, Technician

OTF/108, 303-384-6198

Task Focus:

Environmental chamber testing of PV modules

Specializes in:

Chamber calibration, maintenance, and repair; machining and other lab support.

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Photo of Jose Rodriguez.

Jose Rodriguez

Jose Rodriguez, Technician

OTF/108-04, 303-384-7819

Task Focus:

System Design, Installation, and Testing

Specializes in:

Maintaining automated I-V tracers in the field.

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Photo of Bill Sekulic.

Bill designs, installs, and monitors PV systems such as this one, in the OTF array field.

Bill Sekulic, Engineer

OTF/123, 303-384-6362

Task Focus:

PV Module/System Technology Testing and Validation

Specializes in:

PV system design, test fixture development, and maintenance; data acquisition design; Labview programming; computer and electrical systems development.

Known for:

Creative solutions for reliability testing and test bed development.

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Photo of Timothy Silverman.

Timothy Silverman

Timothy Silverman, PhD, Scientist

OTF/203, 303-384-7912

Task Focus:

Lifetime prediction of die attach of CPV modules. Understanding metastabilities in thin-film modules.

Specializes in:

Finite element analysis.

Known for:

Modeling and accelerated testing of die attach in CPV modules.

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Photo of Ryan Smith

Ryan Smith

Ryan Smith, Engineer

Task Focus:

Outdoor Module Testing

Specializes in:

Quality assurance of data collection from module performance and associated metrology; RMIS monitoring.

Known for:

Establishing the PVDAQ data base.

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Photo of Kent Terwilliger.

Kent works with an assortment of accelerated testing equipment, including the Atlas CI65, to troubleshoot experiments and test samples.

Kent Terwilliger, Research Technician

FTLB/168-131, 303-384-6254

Task Focus:

Environmental Testing of PV Modules

Specializes in:

Maintenance and operation of environmental testing; tracking of module testing.

Known for:

Troubleshooting and repairing environmental test chambers.

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Photo of John Wohlgemuth.

John Wohlgemuth

John Wohlgemuth, PhD, Principal Scientist

SERF W103, 303-384-7982

Task Focus:

Standards development, module failure analysis and the development of accelerated stress tests for PV

Specializes in:

Understanding and documenting failures in silicon and thin-film modules

Known for:

Convenor of IEC TC 82 WG2; 30 yrs at BP Solar

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