Mary Ann Piette is the Interim Associate Lab Director of the Energy Technologies Area at Lawrence Berkeley National Laboratory. She manages a research enterprise comprised of 700 staff and affiliates, including 120 principal investigators working across a broad set of technology R&D programs to accelerate decarbonization ranging from demand-side energy efficiency and grid integration to hydrogen technologies, energy storage, and renewable energy systems. We had a terrific time talking to Mary Ann about her mechanical engineering background and how she thinks about buildings, energy, comfort, and grids. She’s focused on four pillars of decarbonization: energy efficiency, electrification, grid integration, and distributed energy resources.She wrote a chapter for a new book, Women in Renewable Energy (by Katherine T. Wang and Jill S. Tietjen (Springer, 2023) about using building loads dynamically for low-carbon energy systems. “When we change our electricity system to be based on wind and solar, we need to integrate with demand side systems,” she says. “Grid-scale storage is important, but flexible demand can be much more cost effective.” And she points out that this is part of a significant gap in current built environment conditions. “If we are are going to accelerate progress, we need to understand and utilize the feedback between design and operations.”