Older GPUs make more heat. We sell it.
For the same AI workload, a previous-generation GPU draws more electricity than a new one, and nearly all of that electricity leaves the chip as heat. In an ordinary data centre, that heat is a cost. On a heat network, it’s something to sell.
Refurbished A100 fleet
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New H100 fleet
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Where the electricity goes
A server turns electricity into computation, and almost all of that electricity ends up as heat. Newer chips do more work per watt, so a given job draws less power and gives off less heat.
How much of that heat can be recovered, and at what temperature, depends on the cooling. Liquid-cooled racks give off hotter, more concentrated heat than air-cooled halls, and hotter heat is cheaper to lift to network temperature. We design each site’s cooling with the heat network in mind.
The figures above are illustrative. The real ratio between generations depends on the model, batch size and how busy the cards are. We model it for each project.
Heat first, compute second
Hyperscale sites are built to use as little energy per computation as possible and to get rid of heat. We start at the other end: a heat source sized to a local demand, with compute that pays for the electricity.
Cheaper hardware
Cards coming off hyperscaler contracts cost a fraction of new ones. That keeps compute affordable for buyers who need sovereignty, not frontier-scale training.
A second life
Running proven hardware for longer makes more use of the carbon already spent making it.
More heat per job
The less efficient chip gives off more heat for the same work, and that heat has a buyer.
A better planning story
To a council, “a heat source for the leisure centre” is easier to support than “a data centre that gives some heat away”.
The trade-off, stated plainly
More electricity per job means a higher power bill for each unit of compute. The model works where heat income and cheaper hardware together outweigh that cost. That depends on the price of power, the heat contract and the workload.
We test that for each project before it goes anywhere. Where the numbers favour newer hardware, we’ll use it. The heat still gets sold.
Got heat, or need it?
Whether you run a data centre or need low-carbon heat for a building, we can tell you quickly whether there's a project in it.