PVSC PROGRAM

Tutorial AM2: PV Systems Modeling with Python, an Interactive Introduction

Instructors:
Adam R. Jensen, Technical University of Denmark (DTU), Denmark
Umay Akkoseoglu, DNV

Tutorial Description
PV modeling is used during all stages of PV projects, including pre-feasibility studies, plant layout optimization, and management of operational assets. Modeling tools for all aspects of photovoltaic systems are rapidly growing, and there are solutions for many research questions you might want to explore. Python has become the main scientific language for open-source PV modeling, and many open-source tools are now available for PV modeling. This tutorial will focus on teaching attendees PV modeling in python through pvlib.

In this interactive tutorial, we will go from getting acquainted with some common data used or measured in PV systems (i.e., weather) to modeling the AC energy output of a single-axis tracker system. This includes learning and simulating sun position, plane-of-array irradiances, temperature models, and inverter output. We will review common vocabulary around Python and common PV data aggregation by hour, week, month, and visualization. The tutorial will finalize with an overview of other available open-source tools for other aspects of modeling PV systems and novel ideas on data science in the PV field.

Adam R. Jensen is a researcher at the Technical University of Denmark (DTU) working with performance modeling of PV systems and solar resource assessment. His focus is on optimizing irradiance availability for solar energy systems through enhanced tracking strategies and shade avoidance. As part of his research, he is a core developer of pvlib python and regularly teaches workshops to beginners and experts. Adam holds a PhD in concentrated solar power and a master’s degree in sustainable energy from DTU.

Umay Akkoseoglu is a solar energy analyst at DNV and part of the solar energy assessment team. Her work includes solar performance modeling for project financing, advancing the state of the art of solar energy analysis methods, and automating processes using python and SolarFarmer. Umay has worked in solar energy for the past four years and recently has supported work on spectral correction, bifacial gain analysis for trackers, and SolarFarmer 3D modeling. Umay holds a Bachelor's degree in Environmental Engineering from University of California, San Diego.

Tutorial AM3: Perovskite and Tandem Packaging and Reliability

Instructors:
Chiara Barretta, PCCL, UK
Michael Owen-Bellini, National Renewable Energy Laboratory, USA

Description
TThe tutorial will provide a comprehensive overview of polymers and encapsulants used in photovoltaic (PV) modules, with a special focus on encapsulation concepts for modules with perovskite and tandem cells. Polymer fundamentals will be introduced, highlighting key properties relevant to PV applications based on new cell technologies. Encapsulant requirements for PV will be discussed, covering traditional designs (glass/backsheet), evolving trends like glass/glass modules, and including next-generation cell technologies. Different polymer types, including thermoplastics and thermosets, will be explored with a focus on processability and performance. Encapsulation of modules with perovskite and tandem solar cells will be discussed in detail, including how polymeric encapsulants can influence module durability and lifetime. Finally, recent advancements and open challenges, complemented by new data on encapsulant performance in these next-generation technologies will be presented.

Chiara Barretta is a researcher at Polymer Competence Center Leoben in the division of “Sustainable Polymer Solutions”, based in Leoben (Austria). Her research is focussed on polymers (encapsulants and backsheets) used in photovoltaic applications. Chiara received her Ph.D. in Material Science and Testing of Polymer from the University of Leoben in 2023. Her work includes development of destructive and non-destructive characterization methods able to describe polymer degradation in PV modules, understanding of degradation mechanisms of PV materials under artificial and real environmental aging conditions, and optimization of processing conditions (such as lamination) according to bill of materials.

Michael Owen-Bellini is a staff scientist at NREL. He specializes in accelerated stress testing and packaging for PV modules. In 2017 he completed his PhD at Loughborough University in the UK where his thesis was topic was understanding PV module mechanics with respect to the encapsulant. At NREL his efforts are focused on understand accelerated stress testing and packaging needs for both incumbent and emerging PV technologies, including metal halide perovskites and tandems.

Tutorial AM4: Design of Experiments (DOE) Demystified—Practical Strategies: Optimize Experiments and Modeling to Accelerate Your Research

Instructors:
Muhammad Alam, Purdue University, USA
Dirk Jordan, National Renewable Energy Laboratory, USA

Description
Maximizing the information gained while minimizing time, effort, and expense is essential—everyone does experiments, but the principles of “Design of Experiments” (DOE) tell us how to do them effectively. DOE is a structured approach to collecting data and making discoveries by studying the relationships between multiple input variables and key output responses. Traditional methods, such as the one-factor-at-a-time approach (where only one factor is varied at a time while all others are held constant), are time-consuming, inefficient, and prone to missing interactions between input variables. However, in cutting-edge research, such interactions are common and often critical to understanding complex systems. In this context, the physics-based approach grounded in the Buckingham Pi theorem combined with statistics developed by Fisher, systematically reduces the number of variables to be analyzed and experiments required to reach reliable conclusions. More frequently employed in manufacturing for rapid improvement and essential quality control, this methodology is greatly underutilized in research.

This interactive tutorial will provide the foundations of DOE and demonstrate why it is indispensable for studying the impact of multiple variables. Through numerous examples—many drawn from our combined 40 years of experience, ranging from thin-film deposition to machine learning (ML)—we will illustrate the method’s practical value. Hands-on exercises using Google Colab will provide participants with the opportunity to gain a working knowledge of DOE, including selecting appropriate designs, conducting experiments, and analyzing results. We will also discuss the potential for DOE to save energy and computing power in conjunction with machine learning and artificial intelligence (AI).

Muhammad Alam is the Jai N. Gupta Distinguished Professor at Purdue University, where his research focuses on the physics and technology of semiconductor devices operated in extreme environments. He started his career in 1995 at Bell Laboratories, Murray Hill, NJ. Since 2004, Dr. Alam has authored over 400 papers on the fundamental performance limits and reliability physics of transistors, biosensors, and solar cells. He is a fellow of IEEE, APS, and AAAS, and has received the 2006 IEEE Kiyo Tomiyasu Medal, the 2015 SRC Technical Excellence Award, and the 2018 IEEE EDS Award. Dr. Alam's web-enabled courses have reached over 500,000 students globally, making significant contributions to semiconductor device education worldwide. His book "Principles Of Solar Cells: Connecting Perspectives On Device, System, Reliability, And Data Science" has recently been published by World Scientific.

Dirk Jordan is a Distinguished Member of Research Staff at the National Renewable Energy Laboratory in Colorado, USA. He has been researching PV performance, reliability and degradation of modules and systems for 15 years. He has been using Design of Experiments (DOE) for more than 20 years for a diverse set of technologies ranging from PV reliability to thin-film deposition and machine learning. He received a Ph.D. in physics from Arizona State University and a B.S. in physics from the University of Heidelberg, Germany.

Tutorial PM1: Tandems and Multijunction Photovoltaics

Instructor:
Myles Steiner, National Renewable Energy Laboratory, USA
Emily Warren, National Renewable Energy Laboratory, USA

Tutorial Description
This tutorial will give a general introduction to the field of tandem solar cells for the use in terrestrial and space systems. It will start from basic theoretical considerations and explain the benefits of using several pn-junctions to convert the broad solar spectrum into electricity. Since III-Vs have historically dominated the field of multijunctions and high efficiency photovoltaics, we will review III-V multijunctions as a model system for other tandems. Some of the specific requirements for the use of multijunctions in different environments will be discussed, such as high current capacity for concentrators, radiation hardness for space applications, and low cost for one-sun applications, and some emerging applications will be introduced.

New and on-going efforts toward hybrid tandems, combining cells of different material systems, will then be covered in detail. Silicon- and perovskite-based tandem devices offer the promise of similarly high conversion efficiencies as traditional tandem III-Vs, but at a fraction of the cost. However, these integrated materials systems also come with unique issues that arise due to the various dissimilarities between the materials and the fabrication processes required for different technologies. We will look at the advantages and disadvantages of different material and interconnection combinations (e.g. 2T, 3T, 4T) in terms of efficiency, cost, and scalability.

Myles Steiner is a senior scientist at the National Renewable Energy Laboratory, in Golden, Colorado, where he leads NREL’s III-V Photovoltaics Core program. His work focuses on the development of III-V multijunction solar cells for terrestrial and space power generation, thermophotovoltaics for energy storage, and solar fuels by photoelectrochemical generation.

Emily Warren is a Group Manager at the National Renewable Energy Laboratory, in Golden, Colorado, where she leads the High Efficiency Tandems, Cell & Module Performance Group as well as co-leads the Perovskite Enabled Tandems Core program. Her research interests focus on the fabrication and modeling of multi-terminal tandem solar cells and modules. She also studies novel architectures for the creation of solar fuels and dabbles in heteroepitaxial growth of III-V materials on silicon and nanoimprint lithography.

Tutorial PM2: Emerging Space Photovoltaics: Unique Semiconductors, Device Designs and Radiation Interactions

Instructor:
Ian R. Sellers, University of Buffalo, USA
Ahmad R. Kirmani, Rochester Institute of Technology, USA

Tutorial Description
Space applications have long been a driving force for innovation in photovoltaic materials and devices, since the launch of the first solar power satellite, Vanguard I, in 1958. Space power systems have a unique set of requirements including high specific power and tolerance to radiation exposure, necessitating space specific solutions. In recent years the space sector has seen rapid evolution with commercialization of the sector and increasingly widespread use of space-based services including global communication networks and the future prospect of space based solar power, as well as ambitious targets for space exploration and discovery science in space. The photovoltaic power system is critical to enabling these exciting new possibilities. This tutorial will cover space applications and environments relevant to the new space era. This will discuss current commercial technologies and the evolution of such, and then next-generation space power concepts including ACIGS and metal-halide perovskite semiconductors, which are being pursued with intense vigor owing to their unique radiation tolerance and potential for lightweight deployable architectures. The tutorial will be delivered in two parts.

Part 1: Space PV requirements and challenges of this environment

a. Design of current commercial space PV systems
b. Radiation damage mechanisms in conventional space PV materials
c. Practical tools for simulating radiation environments, mission profiles and corresponding solar cell damage – consideration of planetary conditions
d. Evolution of the space sector driving design innovation in commercial systems: III-V to ACIGS and beyond

Part II: Metal-halide perovskite space solar cells

• a. Unique radiation-matter interactions in perovskite semiconductors
  b. Soft lattice nature and healing phenomena in perovskite semiconductors
  c. Perovskite solar cell device architectures for space compliance
- Ultralight packaging strategies for space power
- Challenges beyond radiation tolerance and near-future focus areas

Ian Sellers received his BEng from the Department of Electrical & Electronic Engineering at the University of Liverpool in 1999, a MSc from the Dept. of Physics at Imperial College London in 2001, and a Ph.D. in Physics from the University of Sheffield in 2004. Between 2004 – 2006, Dr. Sellers was a Marie Curie Fellow at CRHEA-CNRS in Valbonne, France, a position that was followed by a postdoctoral position at the University at Buffalo in the United States. In 2008, Dr. Sellers joined the Solar Energy and Technology Group as a Senior Research Scientist at Sharp Laboratories of Europe in Oxford, UK. After spending three years in Industry, Dr. Sellers returned to the Academic environment taking a position at the University of Oklahoma in 2011 where he rose to the position Ted S. Webb Presidential Professor of Physics. In August 2023, Dr Sellers joined the faculty in Electrical Engineering at the University at Buffalo. Professor Sellers’ research is focused on the development and investigation of novel materials and devices for next generation photovoltaics and space power applications.

Ahmad Kirmani is an Assistant Professor in the School of Chemistry and Materials Science at Rochester Institute of Technology (RIT), where he leads the Interface and Structure in Printable Inorganic Electronics (INSPIRON) laboratory with a focus on inkable semiconductors for terrestrial and space applications. Previously, as a postdoctoral researcher at the National Renewable Energy Laboratory (NREL), Dr. Kirmani led the perovskite space power research program exploring radiation effects in perovskite solar cells and developing space-compliant device architectures. His research has resulted in over 65 peer-reviewed journal articles on solution-processed semiconductor optoelectronics including colloidal quantum dots, metal oxides, and perovskites. Dr. Kirmani serves as the task lead for RIT at the Advanced Space Power Materials and Architectures (ASTROMAT) center – a $10 million initiative funded by the United States Space Force to advance next-generation space power technologies.

Tutorial PM3: Performance Testing of PV Cells and Modules

Instructor:
Tao Song, National Renewable Energy Laboratory, USA
Nikos Kopidakis, National Renewable Energy Laboratory, USA

Description

• 1. Fundamentals
a. Definitions: irradiance (total, spectral), Standard Test Conditions (STC)
b. PV testing basics – Spectral response, current-voltage (I-V) characteristics
c. Translation of indoor test to STC – spectral mismatch, temperature corrections
d. Performance testing of PV modules
e. The PV calibration chain, traceability, and the meaning of “ISO accreditation”
f. International Standards
• 2. Industrial Silicon cells and modules
a. Challenges of multibusbar M10, M12 silicon cells
b. Probing methods for busbars and busbar-less cells for IV testing
c. Silicon module testing in the lab and in a production line
• 3. Emerging PV Cells and Modules including perovskites
a.Dynamic current response & I-V Hysteresis on perovskites
b. Steady-state measurement approaches: MPPT & Asymptotic IV
• 4. Performance measurement on multijunction cells (e.g., 2-terminal(T), 3-T and 4-T
a.Quantum efficiency measurement strategy and associated artifacts
b. Spectral irradiance adjustment approaches
c. Detailed I-V characterization of MJ cells
d. Characterization of 3-T and 4-T tandem cells

Tao Song is a research scientist in the PV Cell and Module Performance Group at NREL and has led the cell performance calibration since 2018. He received his Ph.D. in physics from Colorado State University in 2016, with a research focus on device characterization and simulation of thin-film CdTe and CIGS solar cells. Then, he joined NREL as a post-doc for 1.5 years before promoting as a staff scientist. His research interest covers the high-precision efficiency calibration of any kinds of solar cells and the development of reliable measurement techniques for novel and emerging PV devices.

Nikos Kopidakis is a research scientist at NREL and the technical lead of the PV Cell and Module performance group. He has over 20 years of experience in PV research, including silicon, dye-sensitized and organic PV. His interests cover the performance characterization of PV cells and modules of any size and technology and new measurement techniques for novel and emerging PV. He has previously worked on new materials for PV applications and in spectroscopic techniques for characterizing their photophysics.

Tutorial PM4: Agrivoltaics: Unlocking the Potential of Dual Land Use

Instructor: Silvana Ovaitt, National Renewable Energy Laboratory, USA
Uzair Jamil, University of Western Ontario, Canada

This tutorial will delve into the practical and technical considerations for agrivoltaic systems, including crop selection, agricultural practices, and solar energy optimization. Leveraging insights from successful case studies, we’ll address challenges such as policy barriers and regulatory gaps while exploring opportunities and incentives for implementation. With a focus on PV expertise, attendees will gain actionable knowledge on designing and evaluating dual-use systems that balance energy generation with agricultural productivity

Silvana Ovaitt is a researcher at the National Renewable Energy Laboratory (NREL), working within the Field Performance and Reliability Group. Specializing in bifacial photovoltaic (PV) technology, Silvana's work primarily revolves around the optical and electrical performance and modeling of bifacial PV systems. Her research interests also extend into the Circular Economy, where she develops tools to research and quantify the impacts of various circularity pathways on PV’s sustainability within the broader context of the Energy Transition. Silvana also leads the Hands-on PV Experience (HOPE) Workshop at NREL, a well-established program now in its 13th year. This week-long immersive event offers PhD students hands-on, industry-relevant experience with photovoltaic technologies directly within NREL’s advanced laboratories.

She is the recipient of the 2024 Star Award from the Society of Hispanic Professional Engineers, the 2024 Powermark Prize in PV Reliability for Early Career, and a selected alumna of the US National Academy of Engineering's Frontiers of Engineering conference. She holds a PhD in Electrical and Computer Engineering and a Master degree in Optical Sciences, both from the University of Arizona. Silvana’s academic and professional endeavors illustrate her deep commitment to advancing renewable energy technologies and mentoring the next generation of researchers in this vital field.

Uzair Jamil is a PhD candidate at the University of Western Ontario, leading agrivoltaics research. His work explores the integration of renewable energy and agriculture, with a focus on optimizing energy generation, crop yields, and system efficiency. He has made significant contributions to agrivoltaic system design, including innovative racking solutions, modeling crop-specific applications, and analyzing the effects of solar panel transparency on agricultural productivity. In addition to technical advancements, his research addresses agrivoltaic policy frameworks and strategies for scaling these systems in diverse climates. Uzair’s interdisciplinary approach emphasizes the practical implementation of sustainable, net-zero agrivoltaic solutions, combining engineering innovation with policy insights to support global energy and food security goals.

Before transitioning to academia, Uzair gained extensive experience as a Mechanical Engineer in the energy, automotive, and petrochemical industries. He is skilled in the maintenance, monitoring, analysis, and repair of rotating and static equipment, including steam turbines, boilers, multi-stage pumps, compressors, and fans. He has successfully led major projects such as a 323 MW Turbine Retrofit with GE and feasibility studies for RFO-to-coal boiler conversions at Hub Power Station. His industrial expertise extends to executing outages, storage tank repairs, and leading Project VIGO/Fortuner (2016-17) at Toyota Indus Motor Company Ltd. Uzair is also the Founding Director of Agrivoltaics Canada, a not-for-profit organization dedicated to integrating farmer-centric advancements in the realm of agrivoltaics, and a Certified Energy Manager and Auditor accredited by the National Energy Efficiency & Conservation Authority (NEECA), Pakistan.

 

Tutorial PM5:PV Systems Modeling with Python, an Interactive Introduction

Instructor:
Silvana Ovaitt, National Renewable Energy Laboratory, USA
Madison Ghiz, DNV, USA

Description
From development to deployment and management of assets, PV modeling is an exciting area with challenges and the use of big data from weather to performance monitoring. Modeling tools for all aspects of photovoltaic systems are rapidly growing, and there are solutions for many research questions you might want to explore. Python is becoming one of the scientific languages of choice, and many open-source tools are now available for PV modeling. This tutorial will focus on teaching attendees PV modeling in python through PVlib.

In this interactive tutorial, we will go from getting acquainted with some common data used or measured in PV systems (i.e., weather) to modeling the AC energy output of a single-axis tracker system. This includes learning and simulating sun position, plane-of-array irradiances, single-diode models, temperature models, and inverter output. We will review common vocabulary around python and common PV data aggregation by hour, week, month, and visualization. The tutorial will finalize with an overview of other available open-source tools for other aspects of modeling PV systems and novel ideas on data science in the PV field.

It is highly recommended attendees of this tutorial bring their laptops. No pre-installed software is needed.

Silvana Ovaitt (nee Ayala Pelaez) is a researcher at NREL working with the performance and reliability group on bifacial photovoltaic (PV) technology. Her focus is on bifacial PV optical and electrical performance and modeling, as well as Circular Economy. As part of her research, she enjoys developing open-source tools to explore and teach PV science. She is also the PI for the Hands-on PV Experience (HOPE) Workshop for PhD students at NREL. She has a PhD in electrical and computer engineering from the University of Arizona, and a master's degree in optical sciences at the same university.

Madison Ghiz is a solar energy analyst at DNV and part of the special projects team in energy assessment. Madison has been working in solar energy for the past 3 years, and recently has supported work on energy assessment validation, HMC, and SolarFarmer. Before joining DNV, Madison earned a Masters degree at Scripps Institution of Oceanography in geoscience, where her research focused on atmospheric physics driving Antarctic surface melt.