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In this new blog series, we ask Energy Department researchers about their life as scientists working with energy efficiency and renewable energy technologies. Our aim is to inform readers about how scientific research is performed, learn from the people who produce our technological marvels, and to increase awareness of how this work impacts our nation’s energy needs.

Our first interview is with Dr. Sarah Kurtz, research fellow, National Renewable Energy Laboratory (NREL), Golden, Colorado; professor, University of California-Merced. Charlie Gay, director of the Solar Energy Technologies Office, sums her up in one word — passionate.

“For over 30 years, I’ve had the pleasure of working with Sarah Kurtz in various roles including the Director at NREL.  In fulfilling her responsibilities in varying roles, Sarah has developed technologies, mobilized diverse stakeholder groups and crafted information in form and substance suitable for a wide range of audiences. All of Sarah’s efforts are unified by a motivation to deliver unwavering support for globally affordable and reliable solar power.  In her dual role as an NREL Research Fellow and as Professor at UC-Merced, Sarah continues to inspire all of us and will lead future generations to even higher achievement.  Thank you, Sarah.”

Kurtz began working at the Solar Energy Research Institute—now the National Renewable Energy Laboratory (NREL)—in 1985. Educated as a chemical physicist at Harvard University, she is best known for her work at NREL in III-V multi-junction cells and for her efforts to improve the reliability and quality of solar energy systems.


Dr. Sarah Kurtz, research fellow, National Renewable Energy Laboratory (NREL), professor, University of California-Merced
Dr. Sarah Kurtz has worked in solar for more than 30 years
National Renewable Labortory

How did you decide on a career in science?

I always did well in math and enjoyed it. But it wasn’t clear what practical value math would provide by itself, so I thought I could apply my math skills to science. I was fortunate to have the opportunity to work with those who were looking for ways to solve the energy crisis in the late 1970s. 

Like most people, I am very pleased when I can do a little something to make the world a better place. Enabling solar energy in the United States appeared to be a wonderful opportunity.

What are the biggest challenges you've encountered as a scientist?

The two biggest challenges I have undertaken are creating high-efficiency multi-junction III-V cells and improving photovoltaic (PV) reliability.

With high-efficiency multi-junction solar cells, the challenge is doing everything right at the same time. It’s a little like being an Olympic gymnast—even a small hesitation could prevent getting the perfect score. There were many challenges along the way.

Growth of a multi-junction cell may include more than 50 steps—sometimes more than 100 steps—and each of these steps requires specifying between one and two-dozen control values like gas flow rates, gas flow direction, temperatures of baths and temperature of reactor. Merely designing the “recipe” that will fabricate the cell requires substantial review for typographical errors.


 If you’d like to contribute to scientific research, consider what position you’d like to “play.”

Dr. Sarah Kurtz

How do you improve PV Reliability?

To improve PV reliability, predicting the long-term durability of PV modules is like trying to hatch an egg in about six hours. Because PV modules can last more than 20 years, we need to simulate these conditions in the lab in a condensed time period to understand their durability and reliability. The solution, historically, has been to overdesign the modules so that they will last a long time, while also trying to improve our ability to understand failures in a more quantitative way. 

Is there any advice you'd most like to give a young student who's thinking about becoming a scientist?

Think about how you’d like to fit in.There are scientists that must market the project to a sponsor; otherwise, there won’t be funding for the work. Some scientists don’t like the marketing part of the job. There are also scientists that might prefer to get the work done in the lab. Many scientists are introverts and would prefer not to spend a lot of time in meetings. Some like programming; others like doing things with their hands.

Getting the job done requires a team. Just as a football team benefits from having a mixture of skills, a research team requires a broad set of skills and contributions. If you’d like to contribute to scientific research, consider what position you’d like to “play.”