Abstract: A gas turbine engine for an aircraft propulsion system includes a turbine section, an exhaust section, an engine case, and a thermophotovoltaic (TPV) assembly. The turbine section and the exhaust section form a core flow path along an axis of the gas turbine engine. The engine case is disposed within the exhaust section. The engine case includes an inner liner and an outer liner. Each of the inner liner and the outer liner extend circumferentially about the axis. The inner liner forms the core flow path through the exhaust section. The outer liner is disposed radially outward of the inner liner and forming an annular cavity between the inner liner and the outer liner. The TPV assembly includes a plurality of TPV cells. The plurality of TPV cells are disposed within the annular cavity.