Robert H. Williams is Senior Research Scientist at Princeton University's Center for Energy and Environmental Studies. His research interests span a wide range of topics relating to advanced energy technologies, energy strategies, and energy policy, for both industrialized and developing countries. A considerable part of his research is focused on energy technologies and strategies for developing countries, where most of the growth in global energy demand will take place, and where environmental and security challenges relating to energy are especially great. He was Chair of the Renewable Energy Task Force for the President's Committee of Advisors on Science and Technology (PCAST) and was the principal author of "Renewable Energy," (Chapter 6) in the 1997 report, Federal Energy Research & Development for the Challenges of the 21st Century and Report of the Energy R&D Panel. He received a B.S. in physics from Yale University in 1962 and a Ph.D. in theoretical plasma physics from the University of California at Berkeley in 1967.