Tactical, Multifuel, Man-Portable Battery Charger

Thermophotovoltaic (TPV) electrical generation is a technology well-suited to the development of highly efficient, compact, lightweight, and reliable sources of electricity. Tn TPV electrical generation, heat generated by combustion is converted to radiant energy by an emitting surface, then to electrical energy by a photovoltaic (PV) cell. The bandgap of the PV cell is tailored to convert the bulk of the infrared (IR) spectrum being emitted. Making the spectrum more monochromatic leads to higher electrical conversion efficiencies; therefore, filtering elements are placed between the emitter and cells to reflect out-of-band radiation back to the combustor for recycling. Theoretically, TPV electrical generation can exceed 35%. Importantly. TPV generators are totally static; with no moving parts they produce no noise or vibration and can be highly reliable. Essential Research, Inc., teaming with Teledyne Brown Engineering-Energy Systems, propose to develop a rugged TPV power supply to meet the operational requirements requested in the Army SBIR solicitation: person-portable, 200 W output power, and utilizing liquid, logistic fuels. Our technical approach is to develop a combustor that heats a graybody SiC emitter to moderate temperature (1500 K) . The IR radiation is tailored with a shortpass filter that reflects the near out-of-band radiation back to the combustor for recycling. The in-band radiation is converted to electricity with narrow-bandgap PV cells made from InGaAs deposited on InP. BENEFITS: We plan to prototype a 200 w, man-portable battery charger at the end of Phase II. The unit will be capable of generating electricity from burning tactical, liquid military fuels. The unit will have use in the military as a reliable, silent battery charger and remote power generator. Commercial applications include recreational boating and camping, and off-grid power generation.