I suppose for aviation at least this is no less efficient than a gas turbine or a piston, and it's certainly a good deal quieter, has fewer moving parts, and requires less precision engineering than a jet engine. This feels tailor-made for attritable low->medium performance aviation, aka loitering munitions and drones. Strip away the "green" talk, and you're left with something that can burn just about anything (including hydrocarbons like avgas) without the complexity of a turbine.
maybe so. i don't know about attritable for the first applications though. may long range or duration oversight. a large % of the cost is these specialty cells which have not been scaled up to mass production. in the denominator is the intensity of light we can produce, which is based on how high a temperature we can drive, there's a very nonlinear brightness vs temperature. but at 100 suns or so we can get near to $1/W on the cells at startup scale
I can see that being a good use, ultra-quiet ISR that can stay aloft for extended times and doesn't require the complexity of a jet turbine? There has to be enormous demand for that.
Or turn it around a bit. If the entire device could operate at high pressure, then one could imagine putting it inside a jet or rocket engine. Feed it compressed fuel/air mix, burn, extract some energy via thermophotovoltaics, and blast the exhaust out a nozzle or use it to spin a turbine to drive a bypass fan.
An obvious down side is that most jets have very, very high fuel flow and power output, and the area required to extract enough electricity to make this whole exercise worthwhile may be excessive. Also, a lot of military applications are not going to like that sodium illuminant lighting up the exhaust gasses, scattering radar, or otherwise making the plane more visible.
edit: I see that there’s an effort to recirculate the sodium. Maybe that’s enough.
