Hacker News Reader

so my stupid question is, cannot it be used for power? Surely the same system which radiates the heat can be exploited to generate power with something akin to a sterling engine.

View on HN

A heat engine is great when your cold sink is 'free', but here, the cold sink would be the radiator fins, and extracting energy from the temperature difference between main ISS and radiator fins would effectively just make the radiator fins worse at cooling the ISS.

Which is fine if you have lots of excess radiator fins. But they almost certainly don't -- shipping up extra radiator fins in order to get power from the excess cooling capacity would be less efficient than just adding solar cells (efficiency of a heat engine maxes out at 1 - (T_cold / T_hot)).

These radiators exist specifically to deal with power which has already been used. As stated in the article, the station needs a few kW of electrical power. Eventually all this power ends up as a waste heat energy. There is nothing that can be done with it, so it has to be dumped into space.

There's also solar heating of the station itself to worry about. Although to some extent you can make the station reflective (white) to deal with that.

Reply on news.ycombinator.com