Solid Cell Inc. — Department of Defense STTR Phase I: N20A-T023

Description

Solid Cell, in conjunction with Woods Hole Oceanographic Institution (WHOI), proposes a Phase I STTR project to demonstrate the feasibility of an Arctic thermoelectric generator (ATEG) design capable of meeting the performance and technical requirements defined by the Navy in the topic description.  Specifically, the team will develop a concept for a robust and survivable innovative prototype solution to harvest Arctic Ocean thermal energy in-situ and provide low power levels to sensors and data communications while integrated onto a free-floating or ice-tethered Arctic buoy.  The ATEG energy harvesting system will use a unique design to achieve the target technical objectives, while relying on commercially available mass-produced thermoelectric (TE) modules.  A TE module is a solid state devices that convert temperature differences directly into electricity, bypassing mechanical systems associated with conventional thermodynamic cycles.  Each module is comprised of an array of small electrically connected TE elements. The ATEG will support the objectives of the Navy as it continues to implement a persistent unmanned presence in the Arctic Ocean to achieve observational goals, new methods to generate power on-site are required in order to sense the environment and communicate data for assimilation into operational models.  Currently, unmanned Arctic buoys and platforms carry batteries that take up significant weight and volume.  Power generation via solar and wind energy is available, but compromised in the Arctic due to limited sunlight hours and harsh winds that require large, expensive structures for survivability.  Another possibility is the use of thermoelectric generators (TEG) with a radioisotope heat source (RTG) or TEG on propane.  However, such solutions cannot be used for the problem under consideration, primarily for security or reliability reasons.  Developing an innovative capability that uses the thermal gradient between Arctic air and ocean water to generate in-situ power will allow the Navy to harvest an existing energy resource and improve the persistence of observations in the region. The ATEG will support a planned energy persistence level of one year for low power environmental and oceanographic observational sensors as well as gateway buoy data communications.  It will be based on a 500 W thermal harvesting system that can be incorporated into a standard Arctic oceanographic buoy and potentially in a configuration that is moored to the ice.  The two main challenges that will be addressed by the proposed innovation are the energy efficiency of generating power given the relatively low thermal gradient that exists on a daily average in the Arctic and the ability to withstand the harsh Arctic environment.