Jefferson William Tester

Jefferson W. Tester

David Croll Sesquicentennial Fellow and Professor
Smith School of Chemical and Biomolecular Engineering
254 Olin Hall


Dr. Tester is a professor of sustainable energy systems in the Smith School of Chemical and Biomolecular Engineering at Cornell University. He also serves as principal scientist for Cornell’s Earth Source Heat project. Dr. Tester is a Croll Energy Fellow and a Fellow in the Atkinson Center for a Sustainable Future. Prior to his appointment at Cornell in 2009, Dr. Tester was the H.P. Meissner Professor of Chemical Engineering at the Massachusetts Institute of Technology where he served as Director of MIT's Energy Laboratory (1989-2001) and Director of MIT's School of Chemical Engineering Practice (1980-1989). His research on geothermal and biomass energy extraction and conversion and environmental control technologies has resulted in over 300 scientific publications and 13 co-authored books. Dr. Tester is a fellow of the Royal Society of Chemistry and was a member of the IPCC's Working Group on Renewable Energy Sources, and advisory boards of the National Renewable Energy Laboratory, the American Council of Renewable Energy, and Idaho National Laboratory.

Research Interests

Energy/Resource Related Problems – Thermal-hydraulic processes for geothermal energy extraction in subsurface rock reservoirs - Geothermal reservoir engineering (tracer transport and rock–water interactions in fractured geothermal reservoirs) - Geothermal heat pumps for integrated cooling and heating applications - Deep drilling in hard rock using chemical-assisted hydrothermal jets - Recovery of critical energy materials using supercritical fluid extraction - Thermochemical liquefaction and gasification processing of waste biomass feedstocks – Integrated energy systems analysis of renewable biomass and geothermal including life cycle and technoeconomic assessment

Applied Thermodynamics and Kinetics – Chemical kinetics in supercritical fluids - Molecular simulations of condensed matter - Properties of aqueous organic and electrolyte mixtures for thermal energy storage and power cycle applications - Rock-water interactions in hydrothermal environments - Salt crystallization/dissolution phenomena in supercritical water - Crystallization/dissolution phenomena in supercritical water

Teaching Interests

Energy systems analysis methods, renewable energy and fossil energy technologies, emphasis on applying quantitative methods using thermodynamic, kinetic and transport fundamentals in the context of scalable practical energy processes operating under environmental and economic constraints.

Selected Publications

  • Hawkins, A.J., D.B. Fox, M.W. Becker, and J.W. Tester, “Measurement and simulation of heat exchange in fractured bedrock using inert and thermally degrading tracers,” Water Resources Research 53, 1210-1230 (February 2017).

  • Zurmuhl, D.P., M.Z. Lukawski, G.A. Aguirre, W.R. Law, G.P. Schnaars, K.F. Beckers, C.L. Anderson, and J.W. Tester, “Hybrid geothermal heat pumps for cooling telecommunications data centers, Energy and Buildings 188-189, pp 120-128 (April 1, 2019).

  • Kassem, N., D. Sills, R. Posmanik, C. Blair, and J.W. Tester, “Combining anaerobic digestion and hydrothermal liquefaction in the conversion of dairy waste into energy:  A techno economic model for New York State,” Waste Management 103, 228-239 (February 15, 2020).

  • Beentjes, I., J.T. Bender, A.J. Hawkins, and J.W. Tester, “Chemical dissolution drilling of Barre granite using a sodium hydroxide enhanced supercritical water jet,” Rock Mechanics and Rock Engineering 53, 483-496 (2020).

  • Tester, J.W., S. Beyers, J.O. Gustafson, T.E. Jordan, J.D. Smith, J. Al Aswad, K.F. Beckers, R. Allmendinger, L. Brown, F. Horowitz, D. May, T.M. Khan, and M. Pritchard, “District geothermal heating using EGS technology to meet carbon neutrality goals: A case study of earth source heat for the Cornell University campus,” Proceedings of the World Geothermal Congress 2020, Reykjavik, Iceland (April 26 – May 2, 2020).

Selected Awards and Honors

  • Excellence in Teaching Award (College of Engineering) 2013

  • Special Achievement Award (Geothermal Resources Council (GRC)) 2011

  • Fellow of the Royal Society of Chemistry 2010

  • Outstanding Faculty Member Award (Massachusetts Institute of Technology) 2004

  • Outstanding Faculty Member Award (Massachusetts Institute of Technology) 2001


B.S. (Chemical Engineering), Cornell University, 1966

M.S. (Chemical Engineering), Cornell University, 1967

Ph.D. (Chemical Engineering), Massachusetts Institute of Technology, 1971


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