Heat pipe

The heat pipe can transport heat over longer distances and connect devices which produce and use heat. Currently, this is limited to heat exchangers, nuclear reactors, and heating towers.

Heat pipes have a heat capacity of 1 MJ/°C. Thus, they can theoretically buffer 500 MJ of heat energy across their working range of 500°C to 1000°C, making them a space-efficient energy store. However, because temperature needs a drop of greater than 1 degree before it will "flow," you can't raise them all the way to 1000°C or drain them all the way to 500°C, so the practical energy capacity will depend on the layout.

As heat pipes rise in temperature, they will give off a very low-distance glow.

On the planet Aquilo, heat pipes are a necessity due to the freezing temperatures. If buildings are not adjacent to heat pipes (or similar objects) with a temperature of at least 30°C, the building will freeze and stop working.