Transformative research issues and opportunities in alternative energy generation and storage

This article presents a summary of research issues and opportunities in alternative energy source research identified by panels of experts assembled by the Engineering Directorate of the US National Science Foundation. The objective was to identify transformative research issues and opportunities to make alternative energy sources viable. The article presents motivations for energy research, grand challenges, and specific challenges in the research areas covered. The grand challenges identified for the United States include supplying 30% of US electricity from photovoltaics by 2030, supplying 25% of US electricity from wind by 2025, displacing 30% of US hydrocarbon use by 2030 with bio-based products, and providing a practical 250–300 W h/kg energy storage system by 2025. Similar challenges could be outlined along the same lines for the remainder of the world. Examples of specific areas of research focus identified as promising include high performance p-type transparent conductors, multijunction thin-film photovoltaic devices, defects in chalcogenide semiconductors, experimental study and numerical modeling of the fluid mechanics of airflow as applied to wind turbines, improved materials for wind turbines, methods for creating high energy density transportable biological feedstocks, biorefinery processes yielding infrastructure-compatible biofuels and biochemicals directly, and improved electrodes and electrolytes for Li ion batteries. Arguments for each of these as research priorities are given.