The US DOE Regional Test Center Program for Emerging Solar Technologies

The Value of the RTC Network to the Nation

Data are vitally important in this era of rapid solar innovation, with its outpouring of new materials and higher-efficiency cell and module designs. Multi-year field reliability assessments under realistic climate conditions should be routinely integrated into the product-development cycle, especially for new cell types and module architectures. Such studies should include high-quality monitoring of components and systems to enable comparative performance assessments and to capture early failures as well as power output over time. The RTCs are a unique national resource that enables US manufacturers to have their products validated across multiple climates.

The RTCs lead to technological Improvements

The RTCs contribute to innovation and growth in the solar industry in multiple ways:

1. Product Validation

The RTCs provide the data and analysis to demonstrate how new products perform over time and in different climates. Companies apply for an RTC study and if accepted, partner with the National Labs on the design and execution of a performance study that best aligns with the partner’s technical objectives. These studies help accelerate the commercialization of new products by quantifying the energy gains of new, high-efficiency solar products and providing the data and analysis needed for investor confidence.  All data are protected by a non-disclosure agreement and shared only with the industry partner unless the partner decides otherwise.

2. Photovoltaics R&D

In addition to supporting industry needs, the RTCs are a catalyst for research, fostering partnerships between the National Labs, universities and private companies to address both mainstream and emerging research challenges of broader interest.

3. Multi-climate Performance Data

Data available to the public includes performance data from each RTC reference PV array, synchronized to onsite meteorological data. The data contributes to advanced performance models, bringing greater accuracy to levelized-cost-of-energy projections.

4. Training and Education

Defined by a world-class infrastructure, exacting protocols and diversity of technologies, the RTCs provide a platform for state-of-the-art solar-training and education, with curricula that reflect collaborations between the local host institution and Sandia.

5. Identification of Emerging Reliability Issues

Photovoltaic materials and module components may respond differently, depending on the operating environment. Cross-climate performance studies can identify early onset reliability problems related to heat, humidity, wind loading and other climatic stressors, enabling manufacturers to take remedial action early in the product lifecycle. The RTCs also generate data on degradation rates, which are important to lifetime performance.

Common Instrumentation and Measurement Platform

The RTCs provide a multi-site, multi-climate platform for product evaluation, representative of high-growth markets for solar.

Each RTC has

• Grid-tied open racking for fast installations and technological flexibility, able to accommodate technologies and systems of varying sizes
• World-class meteorological instrumentation, high-resolution monitoring equipment, and a common set of calibration and operating protocols to ensure data quality across the program.
• Standardized protocols for PV system validation, applicable to different climates and settings.

Irradiance Instrumentation

Instruments produce a set of standardized protocols for PV system validation, applicable to different climates and settings.   

• Global Horizontal Irradiance (GHI)
• Diffuse Horizontal Irradiance (DHI)
• Direct Normal Irradiance (DNI)
• Plane-of-Array (POA)

All irradiance sensors are cleaned twice weekly and calibrated every two years.

Meteorological Instrumentation

• Precipitation gauge
• Wind speed and direction
• Barometric pressure
• Relative humidity and temperature

Reference PV System

Each site also has a 6kW mono-PERC reference PV system, equipped with a high-fidelity monitoring system that includes string-level DC voltage and current measurements, POA irradiance, a POA reference cell and back-of-module temperature sensors. The array provides a common reference to which new module technologies can be compared.

Data Quality

Data is collected at a frequency of about 5 seconds, averaged per minute and transferred to Sandia, where it is analyzed daily.

Automated data reports alert the Labs to any system or data failure at each of the RTC sites, enabling the rapid identification and repair of faulty instrumentation, from sensors to dataloggers.

How to Participate in the RTC Program

Why Partner

The RTCs are a singular resource that gives solar companies access to multi-climate research facilities, high-fidelity performance data and the technical excellence of the National Labs. This unique pairing of industry with Lab expertise helps drive both product innovation and the commercialization of new products. More specifically, RTC participation includes the following:

• Grid-tied infrastructure that can accommodate a diversity of technologies and installation of different sizes
• Access to National Lab expertise and the Lab’s broad engineering and problem-solving capabilities
• Validation approach that includes confidential bankability reports
• Relationship with the RTC Team and National Labs that supports information-sharing and opportunities for future collaboration.

For more information, contact:

Dr. Laurie Burnham
Photovoltaics Research Group
Sandia National Laboratories
lburnha@sandia/gov
505-845-7354

A Multi-Institutional Collaborative

SANDIA NATIONAL LABORATORIES

Laurie Burnham
RTC Program Lead

Bruce King
Principal Investigator and Performance Team Lead for Photovoltaics

Daniel Riley
Instrumentation and Monitoring Lead

NATIONAL RENEWABLE ENERGY LABORATORY

Bill Sekulic
Senior Researcher at NREL and RTC Lead

Chris Deline
Research Engineer and Technical Lead for NREL’s PV System Performance Group.

MICHIGAN TECHNOLOGICAL UNIVERSITY

Paul Dice
Engineering Researcher and Technical Lead for the MI RTC.

Ana Dyreson
Faculty Member and Researcher at Michigan Tech.

UNIVERSITY OF CENTRAL FLORIDA

Manjunath Matam
Faculty Member and Researcher at UCF’s Florida Solar Energy Center

UNIVERSITY OF NEVADA, LAS VEGAS

Aaron Sahm
Research Engineer at UNLV and Technical Lead for the NV RTV

UNIVERSITY OF LOUISIANA AT LAFAYETTE

Six RTC sites

The RTC program has six sites representing a range of climates.

Albuquerque, NM

The New Mexico RTC is co-located with Sandia’s Photovoltaic Systems Evaluation Laboratory, which is a multiple-user facility that conducts research on emerging PV technologies and supports the detailed characterization and performance analysis of modules and components.

Special features include both outdoor and indoor characterization capabilities:

• Two-axis tracker for measuring a module’s performance under controllable conditions.
• High-fidelity meteorological instrumentation including spectral radiometer and sky camera
• Long-pulse, Class AAA solar simulator to measure the electrical performance of modules before and after field deployment
• Imaging chamber for infrared, electroluminescence (EL) and dark current and voltage (dark-IV) measurements for cell and module diagnosticsHigh-security site (badging required)

Golden, CO

The Colorado RTC is co-located with the National Renewable Energy Laboratory’s Outdoor Test Facility. Special features include:

• High-Bay Accelerated Testing Laboratory that allows for accelerated weathering of PV modules under controlled conditions.
• Failure Analysis Laboratory that enables current testing and diagnostic imaging to identify failure mechanisms
• Long-pulse, Class AAA solar simulator to measure the electrical performance of modules before and after field deployment
• Optical Mechanical Characterization Laboratory that supports the optical and mechanical characterization of PV components including their ability to transmit and reflect light and their strength and integrity.High-security site (badging required)

Calumet, MI

Site Partner: Michigan Technological University

• The Michigan Regional Test Center (MI RTC) is in Calumet, Michigan adjacent to the Advanced Power Systems Center at Michigan Technological University.
• The site is distinguished by its climate. The northern Michigan location provides ideal field conditions for evaluating solar technologies in winter: snow and low temperatures here are both predictable and persistent with the average annual snowfall of 202 inches and up to as much 300 inches or more.
• Other features include fixed-tilt racking, single axis trackers, a mock roof and a set of module-scale load sensors that can measure snow, wind and cold loading on modules of any size.

Lafayette, Louisiana

Site Partner: The University of Louisiana, Lafayette

Located at the university’s Solar Energy Lab and equipped with the tools and technical capabilities to support the new RTC. The six-acre solar field is adjacent to Antoun Hall at UL-Lafayette’s Research Park. The facility supports industry-funded studies as well as research. Sandia chose the latest site for its high heat and humidity, as well as the location’s potential for severe weather events, such as hurricanes.   UL-Lafayette will also leverage the RTC to support workforce development for those choosing a career in the PV industry.

Special features include:

• Long-pulse, Class AAA solar simulator to measure the electrical performance of modules before and after field deployment.
• Imaging chamber for infrared, electroluminescence (EL) and dark current and voltage (dark-IV) measurements for cell and module diagnostics.
• Fixed tilt, tracker systems and mock roof structure for product studies.

Henderson, NV

Site Partners: The University of Nevada, Las Vegas and the Southern Nevada Water Authority (SNWA). Located less than 20 miles south of Las Vegas, this site is defined by high irradiance, high heat and limited precipitation.

Special features include:

• Isotype cell sensor for solar spectral measurements
• Technologies represented include: concentrated photovoltaics, mono-crystalline silicon (both n- and p-type), bifacial- and shingled-cell modules, anti-reflective coatings, and sensor adhesives, with more technological diversity on the way.
• Research site for concentrated photovoltaic (CPV) systems
• Installation labor, and other technical assistance, provided by SNWA
• Onsite office for student education and research
• High-security site (badging required)

Cocoa, FL

The FL RTC is located on a 10-acre site owned by the Florida Solar Energy Center in Cocoa, Florida, where the climate is consistently hot and humid.

Site Partner: University of Central Florida

Associated capabilities include:

• A long-pulse Class AAA solar simulator for measuring the electrical performance of modules
• Electroluminescence (EL), infrared (IR), acoustic and optical imaging
• Materials characterization that includes ultraviolet/visible spectroscopy, secondary-ion mass spectroscopy (SIMS), Auger and photo luminescence (PL).