An apparatus for generating electricity via thermophotovoltaic (TPV) energy conversion is described. High efficiency is obtained by introducing a material into a combustion chamber that emits bright near-monochromatic visible light upon heating. This light is then directed to fall on an array of photovoltaic (PV) cells which convert the light to electricity. Heat and infrared radiation that is not absorbed by the PV cells is returned to the combustion chamber to further improve conversion efficiency.