New materials are critical for meeting our future global energy needs and to create the needed disruptive technologies for energy conversion, delivery, storage, and use. Materials discovery is being accelerated by significant advances in theory and high-throughput materials synthesis and characterization to a point where theory and computation can directly guide experimental materials discovery and development. We will present an overview and highlights from the Next Generation for Materials Design (CNGMD) Energy Frontier Research Center (EFRC), a multi-institution center funded by DOE including results from partners at NREL, Lawrence-Berkeley National Laboratory, SLAC National Laboratory, Harvard University, Oregon State University, Colorado School of Mines, and CU-Boulder. Our EFRC team integrates theory and experiment, including high-throughput methods and in-situ characterization, to discover new functional semiconductor materials, particularly metal oxides and nitrides, relevant to energy applications. Our main goal is to develop a systematic methodology to incorporate and actively design for functional metastability. We focus not only on ground-state materials discovery but also on incorporating metastability (i.e. non-equilibrium structures and compositions) into materials design. We are establishing ranges for accessible metastable materials as a function of the chemistry, energetics, and structure by investigating three classes of metastable systems: defects, polymorphs, and solid solutions (alloys). Another aim is to guide the synthesis of new materials. By coupling theory with state-of-the-art in-situ characterization to probe materials growth pathways, we are developing a systematic theory-driven approach to guide the synthesis of new materials—including metastable systems. An overview of NREL’s extensive R&D program in photovoltaics will also be presented along with challenges to address the development of the needed terawatts of global solar energy.