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phs318uyesterday at 11:32 PM1 replyview on HN

But what do you do with all the waste energy? All those MW and GW have to end up somewhere and radiation into a vacuum is the hardest way to dump heat.


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trhwayyesterday at 11:38 PM

At 70-80C (working temp of silicon chips) 1m2 radiates 700-800W, i.e. the heat of 1 GPU like H200 without any need for any cooling equipment beside the radiator itself( and may be some dumb heatpiping) . To acquire that energy you'd need 3-4m2 of solar panels. So a datacenter would be a large field of solar panels with a smaller field of heat radiators in their shadow.

To the commenter below: yes, exactly, this is where my thinking on that started at the cryptocurrency boom - https://news.ycombinator.com/item?id=26289423 - as you don't need close connection between mining GPUs. For AI you'd need to cluster several together while still overall scheme is the same.

>what the equilibrium temperature of a black planar surface is at a given distance from the sun.

it is 120C at the Earth orbit. So you do need to have some reflection, either back through the solar panels, or the radiators to have a reflective back toward the solar panels in the shadow of which they are to be located.

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