Hybrid Energy Harvesting Systems

ABSTRACT: For this Phase II STTR effort, Prime Photonics and Virginia Tech propose to demonstrate a fully packaged hybrid photovoltaic/magneto-thermoelectric (PV/MTG) panel with improved energy conversion efficiency designed for solar powered air vehicles. In addition to acting as an active thermal backplane for the PV, the MTG is designed to maximize thermal to electrical conversion from the available thermal gradient behind PV cells, and at a weight and with scalable fabrication suitable for large arrays aboard solar air vehicles. The MTG will be multifunctional -- providing additional energy per unit weight while also substituting for traditional honeycomb support structures required for packaged PVs. Design of the hybrid PV/MTG is a balance between PV operating temperatures, MTG efficiency, and overall system weight. An increase in PV temperature typically lowers PV efficiency yet the MTG efficiency increases with the rising available temperature differential ( & #61508;T). The Phase II design is expected to add at least 1% efficiency to the hybrid panel with the potential to add as much as 12% efficiency. Since the MTG backplane can double as support structure the weight penalty is minimal and specific power only increases. BENEFIT: The proposed technology offers an efficient, light-weight, hybrid energy harvesting platform that provides increased specific power (W/kg) and serves as a thermal backplane for solar aircraft photovoltaics (PV's). In addition to solar air vehicles, the technology is also applicable to space and terrestrial solar arrays A secondary product space for the Hybrid Harvester is as a replacement for bulk material thermoelectric generators (TEGs) used for waste heat recovery and energy harvesting for self powered wireless sensors. The device is fabricated using scalable MEMs fabrication techniques, including a novel 3D aerojet printing process, and will allow for easy transition from a research-scale fabrication technique to a larger, commercial scale production process. The tunable design of the device is such that it has efficient thermal capture over a wide range of operation temperatures and can therefore be integrated into nearly any application that has excess thermal energy available.