zlacker

>>pseudo+(OP)
> Some parts of the moon are permanently shadowed and therefore extremely cold, as low as -173 °C. This means that no energy or water would need to be expended to cool the data center.

That doesn't sound right to me. If there's no air, then only black body radiation can be used to cool the data center. That means a massive radiator, a lot larger than a heat-to-air radiator+fan used on earth.

>>M95D+E6
A 1 meter square heat exchanger in a vacuum at 20C will emit about 1 kilowatt at -173C. So about as much as a small space heater per small panel. So a 1 megawatt datacenter would need about 300,000m^2 or 0.3 km^2 of surface area to cool it.

But geothermal cooling would be great on the moon too. Run a pipe 2 meters under the lunar surface and it is -21C.

I think the whole idea though is to make a low wattage space-stead so you can store copies of Moana out of reach of Disney cease and desist letters.

>>foxyv+Qs
> But geothermal cooling would be great on the moon too. Run a pipe 2 meters under the lunar surface and it is -21C.

Isn't the moon geologically dead though - no water or geological movements?

I worry this would just result in the ground absorbing the waste heat and eventually becoming too warm to effectively cool anything. Especially because the ground itself would eventually still be limited by the rate of radiative cooling into space, right?

>>solid_+Ft
You have to worry about changing the ground temperature even on earth FYI. When designing district heating/cooling systems with borehole fields, one of the things that you check for is to make sure that you don’t inject too much heat (or extract too much) seasonally - ideally it’s roughly balanced so any drift year over year is small.

Obviously things like the diffusivity (so conductivity, mass, density etc) of the ground matter a lot, as does the rate of heat exchange at the surface for it to reject (or absorb) heat to the environment.

>>szvsw+pu
Right, I'm roughly aware that's a concern on Earth too which is why I was wondering. How's the thermal conductivity of the moon?

>>solid_+3v
Looked up some papers, and seemingly super low compared to what I would have initially guessed - probably because it’s porous/fluffy/sharp dust with lots of small voids/less compacted I’m guessing. Like, orders of magnitude less than the ground on earth. Not my area of expertise though and was just cursorily skimming papers for values. Specific heat cap and density seem like what you would expect for any rocky materials.