Thermoelectric Power Generation for UAV Applications

There is an increasing need for and development effort in small UAVs (<100 lbs) that can be deployed at the platoon or small unit level in the military. These new vehicles need to be implemented as lightweight, man-deployable systems, yet still retain the essential mission capabilities that larger, more complex UAV systems offer. Since UAV power requirements do not scale linearly with the vehicle’s physical size and weight, there is a need to develop high energy density power systems to aid in the development of smaller UAVs. A promising technology for small UAVs is based on thermoelectric power generation, a process by which thermal heat flux is converted directly to electric power via the Seebeck effect. In previous work, Techsburg and Hi-Z Technology have partnered to develop and integrate thermoelectric generator (TEG) modules onto unmanned micro air vehicle propulsion systems as part of the DARPA MAV (Micro Air Vehicle) program. Techsburg, as the prime contractor, was responsible for TEG system modeling, integration, and testing, while Hi-Z developed and fabricated new high temperature, high efficiency miniaturized TEG modules. In more recent work as part of DARPA’s OAV (Organic Air Vehicle) program, Techsburg has performed system analysis and experiments in support of future application of TEG modules to small UAVs. Techsburg and Hi-Z have demonstrated that with proper TEG module design and system integration, high efficiency thermoelectric generator modules (TEGs) offer a viable alternative source of electrical power for UAVs. The future of thermoelectric technology is very promising. Due to advances in module design, a 300% increase in module efficiency (and power output) is expected within the next 3 to 4 years. With optimal thermal management, systems producing 400 to 500 mW/g or more may be possible. These advances promise a significant enabling technology for extending the endurance and mission capabilities of small, lightweight UAV systems.