# Layer 1 · Physical & Energy

URL: https://justuju.org/layer/physical-energy/

The power, cooling, buildings and chip factories that everything else physically runs on.

Gives the layer above: Electricity, cooling and floor space, plus the fabricated chips themselves.
Needs from the layer below: Nothing in the AI stack: it rests on energy markets, land, water and industrial supply chains.

## Concepts

- [Grid connection & energy supply](https://justuju.org/concept/grid-connection/): A big AI data centre needs a large, steady supply of electricity, and getting connected to the grid can take years, so power, not chips, often decides where and when one gets built.
- [Power & cooling for AI data centres](https://justuju.org/concept/datacenter-power/): AI data centres are limited by how much electricity they can get and how much heat they can remove.
- [Liquid cooling](https://justuju.org/concept/liquid-cooling/): AI racks pack so much power into a small space that fans and cold air can no longer carry the heat away, so water-based cooling is piped right up to the chips.
- [Fabs & the chip supply chain](https://justuju.org/concept/chip-supply-chain/): Advanced AI chips depend on a handful of highly specialised factories, tools and materials.
- [Energy per token](https://justuju.org/concept/energy-per-token/): Each answer a model gives costs a little electricity, and how much depends on what you count: the chips, the rest of the server, idle machines and the building's cooling.

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Justuju · https://justuju.org/ · Content CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Quote with a link to the page.