IEC brings a legacy of significant contributions to the task. It is the oldest solar research facility in the world and one of only two recognized as a Center of Excellence for Photovoltaic Research and Education by the U.S. Department of Energy.

Its work crosses many disciplines, with students from different departments doing fundamental and applied research that relies on electrical engineering, chemical engineering, materials science and physics

UD will celebrate its 50th year with a special event Tuesday, May 3, at the Audion on UD’s Science, Technology and Advanced Research (STAR) campus. It starts at 1:30 p.m., with the 2022 Karl Böer awards. The anniversary celebration starts at 3:30 p.m.

Extraordinary advances have been made in solar technology by IEC researchers, their collaborators and many other scientists and engineers around the world. As a result, solar is now the least expensive way to make electricity in many places.

“The cost of generating electricity from solar will keep coming down for a long time,” said William Shafarman, IEC director and professor of materials science and engineering at UD. “That enables a complete transition to carbon-free energy and makes other things possible. Anything that is energy-limited becomes possible if we keep driving the cost down — whether that is desalination, making fertilizer or scrubbing carbon out of the atmosphere. Eventually, solar and wind should be the way we all get all of our energy.”

There’s plenty of it out there. The sun sends enough energy in an hour to power Earth for a full year.

And the naysayers are fewer and fewer.

“What excites me about the future of IEC and solar research in general is that there is now a very strong and clear awareness of the need for renewable carbon-free energy,” said Steven Hegedus, senior scientist at IEC and a professor of electrical and computer engineering.

“It's not like we have to convince people anymore. Everybody has homes in their communities, in their neighborhood or in their development that have solar on them. There are billions and billions of dollars going into clean technology and solar is one of the biggest beneficiaries of that. The question is, can we get this all to happen quick enough to offset the worst effects of climate change that we're headed toward?”

There are still many challenges to address in capturing, converting and distributing that energy, but the steady advance is impressive. The Department of Energy’s 2021 Solar Futures Study says prevailing market forces, continuing advances in technology and decreasing costs all make it possible that solar energy could provide 40% of the nation’s electricity demand by 2035. With that kind of growth, the report says, the solar workforce of about 230,000 people could expand to 500,000 or even 1.5 million by 2035.

Job creation has been a key policy driver, said John Byrne, UD’s Distinguished Professor of Energy and Climate Policy, director of the Center for Energy and Environmental Policy and an affiliate of IEC.

“Solar creates more jobs per million dollars of investment — two to five times as many as other new electrical generation methods,” he said. “I’d love to say it was the zero-carbon footprint, but it was jobs.”

Connecting with industry leaders has always been an important piece of IEC’s approach.

“When I arrived here in 1986, solar was being used in space, for satellites and things,” Shafarman said. “That’s not what I or most of IEC were interested in. We were interested in making large-scale terrestrial power. We knew it had to be scalable and lower cost and more reliable and those were the goals of the research. Toward those goals, we were always focused on being closely aligned with manufacturing companies and our research projects were targeting manufacturing approaches.”

A key incentive for the rapid expansion of solar in the United States has been the Renewable Energy Portfolio Standard (RPS) that 38 states — including Delaware — now have adopted. It requires electric utilities to include a certain percentage of renewable sources in the energy it provides.

“There is wide consensus in the United States on this,” Byrne said. “It’s all over the country — South, West, East, Midwest. And now 22 states — not yet in Delaware — have said they will go 100% renewable by 2050…. There is going to be a dramatic increase in demand for solar modules. And policy has improved because the consensus is high for sustainable options.”

New policy can rely on the strong performance of today’s advanced technology.

“We have a much better performing photovoltaic cell than we had just 15 years ago,” Byrne said. “It’s much more reliable, it doesn’t conk out and it’s built to last 20 years or more. UD created state-of-the-art cells that now are used all over the world.”

Böer’s leading edge

Böer left Germany after the construction of the Berlin Wall, joining UD’s faculty in 1962. His research focused on the use of copper sulfide and cadmium sulfide in thin-film solar technology.

He brought international recognition as an expert in thin films, a pioneering zeal and a drive to apply research to the practical needs of industry, government and ordinary people.

“Karl was a pioneer, who forced into existence the first thin-film solar cell laboratory in the world,” Byrne said. “And thin film will be what creates the material that is eventually embedded into roofing materials.

“He was the first to produce that kind of cell and he created a research model and an investment model. He was successful on both of those domains.”

Thin-film technology remains a small but fast-growing part of the solar market, with many advantages over the more conventional silicon wafers. Thin films make flexible, lightweight solar panels available, allowing for more options in configuration and application.

“IEC became the focus of thin-film research — copper sulfide, cadmium sulfide, zinc phosphide — but it was developed over the years as a one-stop shop for solar energy,” said Larry Kazmerski, long-time director of Science and Technology at the National Renewable Energy Laboratory in Golden, Colorado. “It didn’t matter if it was silicon or cadmium sulfide, it didn’t matter if you were at the bench or in industry — IEC knew how to do it. They were the resource for photovoltaics in many areas.”

New research is underway that combines thin-film applications, such as the mineral called perovskite, to improve efficiency in conventional silicon cell approaches.

But the underlying objective of the different approaches is the same — to capture and convert as much of the sun’s energy and at as low a cost as possible.

Photovoltaic materials capture the photons (little packets of light) that pour from the sun, converting them into electrons and holes and producing electric voltage and charge flow. Materials science, engineering, physics all are critical parts of the innovative process.

Kazmerski said Böer, who died in 2018, was a hero to him when he was a young researcher. He recalled attending the pivotal 1973 workshop sponsored by the National Science Foundation, where the terrestrial solar program really kicked off. The workshop — "Photovoltaic Conversion of Solar Energy for Terrestrial Applications" — drew 130 scientists from government, academia and industry to Cherry Hill, New Jersey. There, he learned that Böer had won a $1 million grant from the NSF.

“At the time, $1 million was an unbelievable sum,” Kazmerski said. “We were working with grants of about $20,000.”

Thin-film technology expanded greatly until the start of the 2000s, Kazmerski said, when China scaled up silicon wafers and reduced costs significantly.

“China is responsible for the big drop in prices for photovoltaics,” he said, “but in history, the U.S. — IEC and Georgia Tech and others — is responsible for the research.”

IEC’s nimble innovation flexed as discoveries and advances were made.

“One good thing that IEC did that some fall short of, every director — Karl Böer, Allen Barnett, Fraser Russell, Bob Birkmire and now Bill Shafarman — everyone was an outstanding scientist and engineer who had a firm basis in science and technology…. IEC now does silicon and perovskites” Kazmerski said. “Every time you turn around something new comes on the horizon. A research organization like IEC is perfectly set to react to this. And it’s the revolutionary science that drives the technology.”

Solar One

Böer was keen to demonstrate the potential of the work in ways that were easy to understand for the public, political officials, funding agencies and others.

So shortly after the launch of IEC, he and his team undertook a remarkable and unique project — building the first house to be powered and heated solely by solar energy. A chief member of that team was inventor Maria Telkes, who had helped to build a solar-heated house in Massachusetts that focused only on the thermal energy storage features Telkes designed for Solar One.

The two-bedroom house — Solar One — was built just off S. Chapel Street in Newark, Delaware. The small, unassuming building still stands, but only its sharply angled roof offers any hint of its former glory days.

Solar One was dedicated in 1973, just a few months before the oil embargo, and it was an immediate attraction, drawing international coverage and more than 100,000 visitors from around the world in its first year.

“IEC was a trailblazer in another area,” Kazmerski said. “It provided us with the first woman of solar energy. Maria Telkes made huge contributions in solar and did a lot in solar thermal storage. And this provided a pathway, recognizing that women should have a part in science as well.”

The project was not without its challenges, of course. Kazmerski said IEC’s third director — the late T.W. Fraser Russell — loved to tell stories about some of the misadventures.

Thermal storage items were placed in the attic, Kazmerski recalled, but started exploding at one point, creating significant clean-up issues. Adjustments were made.

Residential solar applications became increasingly important as the technology advanced and prices dropped.

Hegedus was the first resident of Newark, Delaware, to install solar panels on his home, which is registered with the state as Solar Two, a name chosen in homage to Solar One.

But when Solar One was built, a lot of what is taken for granted now in such installations simply didn’t exist.

“People had to build and design things by hand,” said Hegedus, who has been at IEC for about 40 years. “Even the switches in the house were different from conventional switches. So they designed a house that was intended to be totally powered by the sun and that meant not just the electricity coming from the solar modules on the roof, which — by the way — were made by graduate students here at IEC because there were no commercially available modules at that time. But they also had to store heat in the form of passive heating as well as active heating. They had fluid running through a different type of solar collector on the roof and they would store that heat in big tubs of salt that were in the basement so that the heat could be used at night to heat the building. It also could store cooling during the day and release that cooling at night.”

President Jimmy Carter was a strong advocate of solar energy and in 1993 was the first winner of the Karl Böer Solar Energy Medal of Merit for his promotion of the technology. During his time in office, Carter had solar panels installed on the White House in 1979, created the Department of Energy and increased funding for research and development in alternative sources of energy, including solar.

President Ronald Reagan later had the solar panels removed, but President George Bush installed a solar thermal system and President Barack Obama had several dozen solar panels installed.

Research advances

No one knows what will be in focus 50 years from now, but new approaches to the solar-energy landscape are underway at IEC.

Last year, the University’s first research solar array was installed in a project Hegedus directs. It includes an energy hub and will be important in research related to integrating solar energy into the electricity grid in new ways.

“It’s not enough to just focus on the solar module, which had been the focus for maybe the first 35 or 40 years of this,” Hegedus said. “We have to look at how we are going to integrate vastly more renewable energy onto the grid because we all know that's what we need to offset the worst effects of fossil fuel electric generation.

“We need to be deploying a lot of solar modules and wind power on the grid. But how do you do that when we're working with last century's grid? It was built for centralized power plants that distributed energy in one direction, namely from the power plant through the transmission line to the local user.

“Now we have local users who are generating electricity. So you've got a grid where power is flowing in different directions than it used to, generated by people who are not utilities — by homeowners, by business owners, by farmers. And that introduces a whole set of both technology challenges and regulatory and policy challenges. Trying to resolve all of these equitably is where we're at today.

“The technological part is what I've been working on lately, and that includes ways of using what are called smart devices, the devices that connect the solar modules to the grid that have a lot of additional features built into them, that sort of sense what's happening on the grid. They adjust to help stabilize the grid.”

Other areas of research include Ujwal Das’ focus on ways to make silicon solar cells better by incorporating thin films to improve performance and reliability with lower cost than conventional manufacturing.

Shafarman’s team continues their research on materials, working to characterize and modify them for maximum efficiency.

And all of the work at IEC helps to generate new leaders in research and development. Scores of doctoral students have come through IEC’s labs. A map of the world is on a wall at IEC, filled with pins designating the location of IEC alumni.

“It created the innovative research talent that then went everywhere — from laboratories to universities to companies, directing their research,” Byrne said. “Almost anywhere you go in the ecosystem of photovoltaics you will find people who did research at IEC. That’s really important. It’s one of the things universities uniquely provide, the intellectual infrastructure that drives research and development into the future.”

Dirk Weiss, who leads technology assessment at First Solar, agreed.

“First Solar has funded forward-looking research with IEC on novel thin-film solar technologies,” he said. “Professor Bill Shafarman’s group has for many years been at the forefront of industry-relevant photovoltaics research.

“His students are world-class. We recently hired a former IEC student into our advanced research team at our California Technology Center in Santa Clara.”

Among the young researchers now at work at IEC are Tasnim Kamal Mouri, a third-year doctoral student from Bangladesh, and Sergio Sepúlveda of Colombia, who recently defended his dissertation.

Mouri is advised by Shafarman, Sepúlveda by Hegedus.

“The main thing I have gotten to experience here was doing 100% experimental work,” Mouri said. “We are trained on different instruments, get to design our own projects and plan our day-to-day research work.”

Mouri has had the opportunity to work with perovskite and silicon solar cells. She hopes to work in research and development in industry.

“It would be a waste if I did all of this experimental work and did not get a chance to change something for the betterment of society,” she said.

Sepúlveda first arrived at UD as a Fulbright Scholar, pursuing his master’s degree in electrical and computer engineering. He took a course on solar energy with Hegedus, was impressed by the labs and — after getting a research scholarship from his government a few years later, asked Hegedus if he would take him on as a student.

Since then, he has worked on simulations of power energy systems and how solar photovoltaics can be integrated into the electric grid.

“I feel like I’m working on state-of-the-art projects,” he said.

He and several others also are working on cybersecurity challenges with Nektarios Tsoutsos, assistant professor of electrical and computer engineering at UD.

“We came up with cyber-attack scenarios and have been testing them,” Sepúlveda said. “We’re trying to find patterns, how inverters respond to cyber attacks.”

He will return to Colombia to teach and continue his research later this year.

“I feel like everything I have learned here has helped me advance my career for the long-term,” he said. “And my adviser not only helped with research, he is also passionate about teaching. He has been very supportive and allowed me to pursue the data science interests I have.

“IEC has definitely played a key role in helping the entire scientific community.”

IEC Directors

Karl W. Böer (1972-75)

George Warfield (acting, 1975-76)

Allen Barnett (1976-79)

T.W. Fraser Russell (1979-1995)

Robert Birkmire (1996-2016)

William Shafarman (2016-present)