Valerie Thomas

Anderson Interface Professor of Natural Systems

Member Of:
  • Center for Urban Innovation
  • Climate and Energy Policy Laboratory
  • School of Public Policy
  • Technology Policy and Assessment Center
Office Phone:
Office Location:
Groseclose 415
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Valerie Thomas is the Anderson Interface Professor of Natural Systems, with a joint appointment in the School of Industrial and Systems Engineering and the School of Public Policy. Her research interests are the efficient use of materials and energy, sustainability, industrial ecology, technology assessment, international security, and science and technology policy. Current research projects include the environmental impacts of alternative fuels, assessment of renewable electricity options, evaluation of alternative vehicle technologies, and energy development in Africa. Thomas received a B. A. in physics from Swarthmore College and a Ph.D. in theoretical physics from Cornell University. From 1986 to 1989, she was a post-doctoral Research Fellow at the Department of Engineering and Public Policy at Carnegie Mellon University. From 1989 to 2004, she was a Research Scientist at Princeton University, in the Princeton Environmental Institute and in the Center for Energy and Environmental Studies, and was a Lecturer in the Woodrow Wilson School of Public and International Affairs. In 2004-05, Thomas was the American Physical Society Congressional Science Fellow. Thomas is a Fellow of the American Association for the Advancement of Science, and a Fellow of the American Physical Society. From 2003 to 2009 she was a member of the US EPA Science Advisory Board. She is currently a member of the USDA/DOE Biomass R&D Technical Advisory Committee. 

  • PhD, Physics, Cornell University
  • BA, Physics, Swarthmore College
Awards and
  • Fellow, AAAS
  • Fellow, American Physical Society
Areas of
  • Energy
  • Industrial Ecology
  • Lifecycle Analysis
  • Sustainability
Research Fields:
  • Clean Energy
  • Climate Change Mitigation
  • Energy Efficiency
  • Energy, Climate and Environmental Policy
  • Transportation
  • Africa (Sub-Saharan)
  • Middle East
  • United States
  • United States - Georgia
  • United States - Southeast
  • Energy
  • Environment
  • Environmental Performance
  • National Security
  • Science and Technology
  • Sustainability
  • PHIL-6000: Responsible Conduct-Res
  • PUBP-6701: Energy Technol & Policy
Recent Publications

Journal Articles

  • Infrastructure Ecology: An Evolving Paradigm for Sustainable Urban Development
       In: Journal of Cleaner Production [Peer Reviewed]

    October 2017

    Increasing urbanization places cities at the forefront of achieving global sustainability. For cities to become more sustainable, however, the infrastructure on which they rely must also become more productive, efficient and resilient. Unfortunately the current paradigm of urban infrastructure development is fragmented in approach lacking a systems perspective. Urban infrastructure systems are analogous to ecological systems because they are interconnected, complex and adaptive components that exchange material, information and energy among themselves and to and from the environment, and exhibit characteristic scaling properties that can be expressed by Zipf's Law. Analyzing them together as a whole, as one would do for an ecological system, provides a better understanding about their dynamics and interactions, and enables system-level optimization. The adoption of this “infrastructure ecology” approach will result in urban (re)development that requires lower investment of financial and natural resources to build and maintain, is more sustainable (e.g. uses less materials and energy and generates less waste) and resilient, and enables a greater and more equitable opportunities for the creation of wealth and comfort. The 12 guiding principles of infrastructure ecology will provide a set of goals for urban planners, engineers and other decision-makers in an urban system for urban (re)development.

  • Parametric Modeling Approach for Economic and Environmental Life Cycle Assessment of Medium-Duty Trucks
       In: Journal of Cleaner Production [Peer Reviewed]

    January 2017

    Using a parametric modeling approach, we evaluate economic and environmental life cycle trade-offs of medium-duty electric trucks in comparison with nine non-electric technologies.

    In terms of cost, whether total cost of ownership or also including health and climate impact costs, model year 2015 battery electric trucks in severe applications such as urban driving provide positive and robust net benefits in many areas of the U.S. However, for typical operations, petroleum diesel with idle reduction or hybrid-electric technology provide the largest overall life cycle cost benefit.

    Battery electric, idle reduction, and hybrid trucks emit lower life cycle greenhouse gas emissions across the board in comparison with the other technologies. Despite lower carbon-intensity, electric trucks tend to be water-intensive because of cooling water consumption for thermo-electric power plants. 

  • Water, air emissions, and cost impacts of air-cooled microturbines for combined cooling, heating and power (CCHP) systems: A case study of in the Atlanta region
       In: Engineering [Peer Reviewed]

    December 2016

    The increasing pace of urbanization means that cities and global organizations are looking for ways to increase energy efficiency and reduce emissions. Combined cooling, heating, and power (CCHP) systems have the potential to improve the energy generation efficiency of a city or urban region by providing energy for heating, cooling, and electricity simultaneously. The purpose of this study is to estimate the water consumption for energy generation use, carbon dioxide (CO2) and NOx emissions, and economic impact of implementing CCHP systems for five generic building types within the Atlanta metropolitan region, under various operational scenarios following the building thermal (heating and cooling) demands. Operating the CCHP system to follow the hourly thermal demand reduces CO2 emissions for most building types both with and without net metering. The system can be economically beneficial for all building types depending on the price of natural gas, the implementation of net metering, and the cost structure assumed for the CCHP system. The greatest reduction in water consumption for energy production and NOx emissions occurs when there is net metering and when the system is operated to meet the maximum yearly thermal demand, although this scenario also results in an increase in greenhouse gas emissions and, in some cases, cost. CCHP systems are more economical for medium office, large office, and multifamily residential buildings.

  • Can developing countries leapfrog the centralized electrification paradigm?
       In: Energy for Sustainable Development [Peer Reviewed]

    April 2016

    Due to the rapidly decreasing costs of small renewable electricity generation systems, centralized power systems are no longer a necessary condition of universal access to modern energy services. Developing countries, where centralized electricity infrastructures are less developed, may be able to adopt these new technologies more quickly. We first review the costs of grid extension and distributed solar home systems (SHSs) as reported by a number of different studies. We then present a general analytic framework for analyzing the choice between extending the grid and implementing distributed solar home systems. Drawing upon reported grid expansion cost data for three specific regions, we demonstrate this framework by determining the electricity consumption levels at which the costs of provision through centralized and decentralized approaches are equivalent in these regions. We then calculate SHS capital costs that are necessary for these technologies provide each of five tiers of energy access, as defined by the United Nations Sustainable Energy for All initiative. Our results suggest that solar home systems can play an important role in achieving universal access to basic energy services. The extent of this role depends on three primary factors: SHS costs, grid expansion costs, and centralized generation costs. Given current technology costs, centralized systems will still be required to enable higher levels of consumption; however, cost reduction trends have the potential to disrupt this paradigm. By looking ahead rather than replicating older infrastructure styles, developing countries can leapfrog to a more distributed electricity service model.