In early March of this year, Ellen Williams stood before an audience of more than 2,000 researchers, entrepreneurs, and policymakers gathered in Washington, D.C., to discuss the future of energy. 

“We are living in a time as dynamic as when Thomas Edison and his contemporaries experimented with electricity,” she declared as master of ceremonies for the Energy Innovation Summit, a conference that included as speakers luminaries such as former Vice President Al Gore and U.S. Secretary of Energy Ernest Moniz. “Drawing upon the science and engineering developments of recent decades, and supported by stunning advances in computational capability, today’s innovators are pushing the boundaries of what is possible with energy.”

Williams should know. As the director for the Advanced Research Project Agency–Energy (ARPA-E), which hosted the summit, she heads an organization that has invested more than $1.3 billion in hundreds of energy-related projects. Her position at the forefront of energy research is the culmination of a long career at the intersection of cutting-edge science, industry, and public policy.

Williams came to Caltech in 1976, having earned her undergraduate degree in chemistry from Michigan State University. While at the Institute, she focused on the emerging science of surface chemistry and physics, the study of the properties of surfaces at the atomic scale. “At Caltech, you were surrounded by such motivated and capable people,” Williams says. “You could really have open, intellectual conversations with just about anybody at any time. I think most people are lucky to experience that one time in their lives.”

Williams also met her husband, Neil Gehrels (PhD ’82), through a student hiking group at the Institute (Gehrels is also a Caltech Distinguished Alumnus this year). “She immediately struck me as incredibly intelligent and a true adventurer,” Gehrels says. “Whether in the lab or out climbing Mount Whitney, she blazed her own trails.” The two were married in Dabney Gardens in 1980. 

After Caltech, Williams and Gehrels moved to Maryland. Gehrels went to work for NASA, and Williams took a position at the University of Maryland, where she continued her research into surfaces, which as a field of study was just beginning to take off. 

At the atomic scale, surfaces—the outer edge of a material—could be elusive to examine. Most forms of microscopy at such levels involved devices that sent beams, such as high-energy electrons or X-rays, which pass right through the objects they examine. Imagine an X-ray photograph of a person; you can clearly see the body and skeleton but not what the face looks like. Researchers wanted to be able to drop down to the smallest scales and literally skim the surface to learn more about the properties of certain materials and how they interact.

Williams recalls the moment she first learned that a new instrument reportedly allowed researchers to probe the edges of silicon. “I was filled with scientific lust,” Williams says. “There is no better way to describe that feeling. I absolutely had to know more.” Once Williams’ research group was able to build their own device, it launched a decade of exploration, beginning with silicon surfaces. “Everything we saw was new. It was a phenomenal 10 years of exploration and discovery, demonstrating new ways of doing science.”

Williams moved from surfaces into cutting-edge research involving nanomaterials and nanoelectronics including organic electronics and graphene. In 1996 she founded the University of Maryland’s Materials Research Science and Engineering Center and served as its director through 2009. During that time, in 2000, she was named a distinguished professor at the university.

     “I believe that we have the technical potential to become a society that thrives using sustainable energy... It’s fundamental for the future of our civilization.”    

“Ellen is analytically one of the most brilliant people I've ever met and knows technology inside and out,” says Drew Baden, chair of the physics department at the University of Maryland. “Her research accomplishments and her leadership in materials research played a huge role in bringing us into the top tier.”

Throughout her career, Williams also took an active interest in science policy. 

In 2009, she chaired a special committee of the National Research Council to review issues related to the Comprehensive Nuclear-Test-Ban Treaty (which the United States has yet to ratify). “There were a number of sobering questions, such as ‘What is our ability to detect nuclear testing?’ and ‘How is the U.S. able to maintain its stockpile without such testing?’” Williams says. “We were able to bring a number of experts to the table and provide a wealth of analysis to help inform policymakers. The good news is that there have been significant advances in detection in the previous decade.” The committee published its report in 2012. 

In 2010, Williams moved from the University of Maryland to become the chief scientist for BP (succeeding former Caltech provost Steven Koonin [BS ’72]). In her role, Williams was responsible for reviewing how new advances in science and technology could contribute to the company’s research and development programs, while also developing a strategic understanding of the supply and use of energy. “We looked at a number of important and unanswered questions," she says. "We know how energy relates to climate, but we also wanted to quantify the additional intersections. How does energy affect the availability and use of other natural resources, such as land, water, and minerals?”

In 2013, President Barack Obama nominated Williams to become director of ARPA-E, and she was confirmed by the Senate the following year. Part of the U.S. Department of Energy, ARPA-E was founded in 2009 out of concern that public investment in new energy technologies was falling behind. Modeled on the Pentagon’s Defense Advanced Research Projects Agency (DARPA), ARPA-E seeks out leading-edge research and technology across the country to invest in. 

“Unlike DARPA, however, our customer is essentially the U.S. economy,” Williams says. “So we also seek to get our technologies on paths to commercial use, where they can transform the energy sector.”

As an example of ARPA-E’s impact, Williams points to recent advances in higher-end battery development for the power grid. “Ten years ago, grid-scale battery storage units might cost $1,000 or more per kilowatt-hour,” Williams says. “We set a goal to drop that to one-tenth the cost, and now ARPA-E performers have demonstrated technologies that are almost there. That is a phenomenal leap that will help transform how we manage our electric power system.”

Since its founding, ARPA-E has invested approximately $1.3 billion across more than 475 projects, 128 of which were announced in 2015. A number of the agency’s seed projects have garnered an additional $1.25 billion in venture capital, a sign of optimism from the private sector for future commercial viability. The results have been impressive enough that President Obama proposed significant increases to the agency in his 2017 budget.

“I believe that we have the technical potential to pivot to become a society that thrives using sustainable energy sources,” says Williams. “But we as scientists must provide policymakers with options that are both technically and economically feasible. I believe it’s fundamental for the future of our civilization.”

photo credit: Scott Council