Session B12: Invited Session: Energy Research at ARPA-E

An Overview of ARPA-E

In less than six years, the Advanced Research Projects Agency - Energy (ARPA-E) has developed and implemented a unique model for the support of energy research and development. ARPA-E funds R\&D on high-potential, high-impact energy technologies that are too early for private-sector investment. The agency focuses on technologies that can be meaningfully advanced with a modest investment over a defined period of time in order to catalyze the translation from scientific discovery to early-stage technology. The fundamental question asked of every ARPA-E program and project is: ``If it works, will it matter?'' This talk will discuss the ARPA-E model, including the development of focused technology programs and the active management of projects for technical and market success. Highlights of programs and projects of particular interest to the physics community will be given.   

No Photon Left Behind: Advanced Optics at ARPA-E for Buildings and Solar Energy

Key technology challenges in building efficiency and solar energy utilization require transformational optics, plasmonics and photonics technologies. We describe advanced optical technologies funded by the Advanced Research Projects Agency - Energy. Buildings technologies include a passive daytime photonic cooler, infra-red computer vision mapping for energy audit, and dual-band electrochromic windows based on plasmonic absorption. Solar technologies include novel hybrid energy converters that combine high-efficiency photovoltaics with concentrating solar thermal collection and storage. Because the marginal cost of thermal energy storage is low, these systems enable generation of inexpensive and dispatchable solar energy that can be deployed when the sun doesn't shine. The solar technologies under development include nanoparticle plasmonic spectrum splitting, Rugate filter interference structures and photovoltaic cells that can operate efficiently at over 400$^{\circ}$C.   

The Solar Vortex: Electric Power Generation using Anchored, Buoyancy-Induced Columnar Vortices

Naturally-occurring, buoyancy-driven columnar vortices (``dust devils'') that are driven by the instability of thermally stratified air layers and sustained by the entrainment of ground- heated air, occur spontaneously in the natural environment with core diameters of 1-50 m and heights up to 1 km. These vortices convert low-grade waste heat in the air layer overlying the warm surface into a solar-induced wind with significant kinetic energy. Unlike dust devil vortices that are typically free to wander laterally, the Solar Vortex (SoV) is deliberately triggered and anchored within a cylindrical domain bounded by an azimuthal array of stationary ground-mounted vertical vanes and sustained by continuous entrainment of the ground-heated air through these vanes. The mechanical energy of the anchored vortex is exploited for power generation by coupling the vortex to a vertical-axis turbine. This simple, low-cost electric power generating unit is competitive in cost, intermittency, and capacity factor with traditional solar power technologies. The considerable kinetic energy of the vortex column cannot be explained by buoyancy alone, and the fundamental mechanisms associated with the formation, evolution, and dynamics of an anchored, buoyancy-driven columnar vortex were investigated experimentally and numerically with specific emphasis on flow manipulation for increasing the available kinetic energy and therefore the generated power. These investigations have also considered the dependence of the vortex scaling and strength on the thermal resources and on the flow enclosure in the laboratory and in the natural environment. Preliminary outdoor tests of a two-meter scale prototype successfully demonstrated the ability to engender and anchor a columnar vortex using only solar radiation and couple the flow to a vertical axis wind turbine. A kilowatt-scale outer door prototype will be tested during the summer of 2015.