Abstract: Various disclosed embodiments include thermionic energy converters with a thermal concentrating hot shell and emitters for thermionic energy converters. In some embodiments, an illustrative thermionic energy converter includes: an emitter electrode; a hot shell configured to concentrate heat flow toward the emitter electrode; a collector electrode; and a cold shell that is thermally isolated from the hot shell.

Abstract: Various disclosed embodiments include combined heating and power modules and combined heat and power devices. In an illustrative embodiment, a combined heat and power device includes a heating system including: at least one burner; at least one igniter configured to ignite the at least one burner; a fluid motivator assembly including an electrically powered prime mover; and a heat exchanger fluidly couplable to the fluid motivator assembly. At least one alkali metal thermal-to-electricity converter (AMTEC) has a high pressure zone and a low pressure zone, the high pressure zone being thermally couplable to the at least one burner, the low pressure zone being thermally couplable to the heat exchanger.

Abstract: Various disclosed embodiments include combined heating and power modules and combined heat and power devices. In an illustrative embodiment, a combined heat and power device includes a heating system including: at least one burner; at least one igniter configured to ignite the at least one burner; a fluid motivator assembly including an electrically powered prime mover; and a heat exchanger fluidly couplable to the fluid motivator assembly. At least one thermophotovoltaic converter has a photon emitter and at least one photovoltaic cell, the photon emitter being thermally couplable to the at least one burner, the at least one photovoltaic cell being thermally couplable to the heat exchanger.

Abstract: Various disclosed embodiments include combined heating and power modules and combined heat and power devices. In an illustrative embodiment, a combined heat and power device includes a heating system including: at least one burner; at least one igniter configured to ignite the at least one burner; a fluid motivator assembly including an electrically powered prime mover; and a heat exchanger fluidly couplable to the fluid motivator assembly. At least one alkali metal thermal-to-electricity converter (AMTEC) has a high pressure zone and a low pressure zone, the high pressure zone being thermally couplable to the at least one burner, the low pressure zone being thermally couplable to the heat exchanger.

Abstract: Various disclosed embodiments include combined heating and power modules and combined heat and power devices. In an illustrative embodiment, a combined heat and power device includes a heating system including: at least one burner; at least one igniter configured to ignite the at least one burner; a fluid motivator assembly including an electrically powered prime mover; and a heat exchanger fluidly couplable to the fluid motivator assembly. At least one thermophotovoltaic converter has a photon emitter and at least one photovoltaic cell, the photon emitter being thermally couplable to the at least one burner, the at least one photovoltaic cell being thermally couplable to the heat exchanger.

Abstract: Various disclosed embodiments include thermionic energy converters and electronic circuitry for generating pulses for igniting plasma in a hermetic package of a thermionic energy converter. In various embodiments, an illustrative thermionic energy converter includes a hermetic package charged with a non-cesium gas additive. The hermetic package is configured to route into the hermetic package pulses for igniting plasma in the hermetic package. A cesium reservoir is disposed in the hermetic package. A cathode is disposed in the hermetic package and an anode is disposed in the hermetic package.

Abstract: Various disclosed embodiments include elements for mitigating electron reflection in a vacuum electronic device, vacuum electronic devices that incorporate elements for mitigating electron reflection, and methods of fabricating elements for reducing reflection of electrons off an electrode. An illustrative electrode assembly includes an electrode. Elements are configured to reduce reflection of electrons off the electrode.

Abstract: Various disclosed embodiments include thermionic energy converters with a thermal concentrating hot shell and emitters for thermionic energy converters. In some embodiments, an illustrative thermionic energy converter includes: an emitter electrode; a hot shell configured to concentrate heat flow toward the emitter electrode; a collector electrode; and a cold shell that is thermally isolated from the hot shell.