This project will use planar dielectric metasurfaces to increase the acceptance angle of solar concentrators. Metasurfaces are extremely thin surfaces with unique properties that change the behavior of light in ways that are counterintuitive to an observer. Currently, existing solar concentrators only work for direct light, which requires a multi-axis tracking system to follow the sun’s path. By achieving a wider acceptance angle, tracking systems will require less movement, which has the potential to lower the cost of the solar collector for a comparable efficiency performance.
This research team will leverage its recent findings on specially designed surfaces that can encode curvature into the phase of planar structured matter. Prototypes of these metasurfaces will be tested at the National Solar Thermal Test Facility, operated by Sandia National Laboratories. Sandia also has nano-fabrication capabilities, which it will use to fabricate and assemble meter-scale metasurface solar collectors.
Current parabolic trough and linear Fresnel CSP systems move throughout the day in order to collect as much sunlight as possible. The new dielectric metasurface concentrators will achieve a wider acceptance angle by depositing a highly-reflective metallic layer underneath the entire planar metasurface, which ensures efficient collection of sunlight. This technology will remove the need for tracking systems and significantly reduce the cost of solar energy.