Hoffman is a graduate of Pennsylvania State University, with both a Bachelor of Science and a Master of Science in ceramic science and engineering. Her 1992 master’s thesis was on “Thermoelastic Properties of Silicon Carbide-Titanium Diboride Particulate Composites.”
Her next responsibilities had her serving both as Deputy Assistant Secretary for Research and Development and chief operating officer within the Office of Electricity Delivery and Energy Reliability. During this time, Hoffman developed the long-term research strategy for modernizing and improving the electric grid. This included developing and implementing sensors and operational tools for wide-area monitoring, energy storage research and demonstration and the development of advanced conductors to increase the capacity and flexibility of the grid. She also initiated a new research effort focused on integrating and distributing renewable energy through the electric grid, such as promoting plug-in hybrid electric vehicles and implementing smart grid technologies to maintain system reliability.
In November 2007, Hoffman was named Principal Deputy Assistant Secretary for the Office of Electricity Delivery and Energy Reliability, a post she held until being selected in November 2009 to take over the office on an acting basis.