A Retrospective of Four Decades of Military Interest in Thermophotovoltaics
Abstract
Following a short discussion on the origin of Thermophotovoltaic (TPV), this presentation offers a retrospective of the progress and results of the recurrent efforts in TPV conducted in the United States by the Military during the last 40 years. The US Army's interest in TPV, for the development of portable power sources, started a few years after the energy conversion approach was conceived. TPV technology was seen to offer a solution for the Army's need for power in the 10 to 1500 Watt range. The technology offered the means to overcome the limitation of size and weight found in existing commercial power sources, with the additional advantage of silent and multifuel operation. Hence, the Army invested research and development (R&D) funding to investigate TPV feasibility for tactical field application. After an initial decade of continuous research studies by the Army, the support for this technology has experienced cycles of significant efforts interrupted by temporary waiting periods to allow this technology to further mature. Over the last four decades, several TPV proof of concept systems were developed. The results of their testing and evaluation have demonstrated the feasibility of the technology for development of power sources with output of several watts to a few hundreds watts. To date, the results have not been found to adequately demonstrate the applicability of TPV to the development of military power generators with output above 500 watts. TPV power sources have not been developed yet for Army field use or troop testing. The development risk is still considered to be moderate-to-high since practical-size systems that go beyond the laboratory test units have not been designed, constructed, tested. The greatest need is for system development, along with concurrent continued component development and improvement. The Defense Advanced Research Project Agency (DARPA) support for TPV R&D effort has been drastically reduced. The Army is still pursuing a 500watt TPV unit demonstrator. No further collaboration among DARPA, Army, NASA is contemplated, which seems indicative of the beginning of a new period of waiting for additional maturing of this technology. The Army's assessment about the viability of TPV for integrated systems indicates that the technology will require a few more years of development. However, at this time, for the completion of component and system development, a strong effort is needed in the private sector. The achievement of the necessary ruggedness for some critical components, acceptable overall efficiency, and system thermal management, is essential for a new, strong restart of TPV effort by the Military.
- Publication:
-
Thermophotovoltaic Generation of Electricity: Sixth Conference on Thermophotovoltaic Generation of Electricity: TPV6
- Pub Date:
- November 2004
- DOI:
- 10.1063/1.1841874
- Bibcode:
- 2004AIPC..738....3G
- Keywords:
-
- 84.60.Jt;
- 84.60.Rb;
- 89.20.Dd;
- Photoelectric conversion: solar cells and arrays;
- Thermoelectric electrogasdynamic and other direct energy conversion;
- Military technology and weapons systems;
- arms control