A Combustion-Based Thermophotovoltaic Electrical Power Generator

Essential Research, Inc. proposes to build a combustion-based thermophotovoltaic (TPV) electric generator using a fossil fuel driven combustor, a selective emitter, a filter, and a photovoltaic cell. The operating point of the heat source and selective emitter will be approximately 1700K. The moderate operating temperature was chosen to provide a system energy conversion efficiency of greater than 20%, low NOx emission, and the high reliability required for military operations. The combustor will have a planar configuration. The selective emitter will be a single or polycrystalline host material (such as garnet) doped with rare-earth oxides. The filter will be a combination of an infrared (IR) reflector filter and a bandpass filter. A narrow bandgap photovoltaic cell will be fabricated by the organometallic vapor phase epitaxy (OMVPE) deposition of InGaAs on InP substrates. The bandgap of the photovoltaic cell will be tailored to optimize the conversion of the selective emitter spectra. We believe that this technology will provide excellent conversion efficiencies in a commercially viable process. At the end of Phase I, we will demonstrate this technology by developing an emitter/filter/cell combination (a converter) having a 20% conversion efficiency. In Phase II, a prototype TPV generator to deliver 100-200 W of electricity will be deployed. A final system efficiency of grater than 20% is anticipated.