• Cocodapuf@lemmy.world
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    23 hours ago

    I’m not sure the moon makes a lot of sense.

    I mean, the two weeks of darkness is the real killer.

    I mean look, let’s say our datacenter requires 100 kw of power. That means about an 800 square m solar array. If you need to store enough power to run the system through a two week night, you’ll need a lot of batteries and a much larger array. You’ll only be collecting power half the time, so the array needs to be twice as large. But there are about 30% losses in transferring energy to the battery, drain over time, and then transferring back, so some quick math says you now need somewhere around 230kw, for a 1800 square m solar array.

    Currently, an array large enough to generate 100kw weighs between 1-2 tons. If we’re optimistic and say 1 ton, that’s 2.25 tons for our equivalent moon array

    Now the batteries. The capacity needs to be enough to store 130kw over the course of two weeks. 130kw x 24hours x 14days = 43,680 kw hours of storage. Lithium ion batteries weigh about 5kg per kwh of storage. 43,680 kwh of storage would weigh 218 tons. And that’s just the base weight of the batteries, I didn’t factor in whatever structures or systems the batteries would need to be usable in space.

    Here’s where I point out that it costs about $5 mil per ton sent to orbit. It costs somewhere between $100 mil and $1 bil to send 1 ton to the moon. Personally, I think it’s a lot easier to send 1 ton to low earth orbit, than to send 220 tons all the way to the moon. I think the only way to make data centers on the moon make sense, would be if you’re already living and working on the moon in a functioning settlement.

    As crazy as orbital data centers are, if your counting in dollars, lunar data centers are literally 10,000 times crazier.