Your radiator may soon run on someone else's training run

A municipal energy utility and the operator of a neighbouring data centre are reported to be negotiating a heat supply agreement covering an estate of several hundred flats. Under the draft, the radiators in those flats would be fed with water that has already passed once through a hall of computers. Nothing has been signed. The utility's term for the arrangement is recovered heat. The residents' association has begun referring to it, in its own minutes, as the weather.

The engineering case is strong and faintly boring. A data centre produces a continuous flow of low-grade heat that it currently pays to push into the open air, and a housing estate wants water at roughly that temperature in roughly that quantity. The novelty is not the pipe. The novelty is the schedule: supply would rise and fall with whatever the building next door is being asked to calculate.

“Nobody's flat would depend on a single customer's workload,” a spokesperson for the utility would be expected to say. “There would be a backup boiler. It would be sized for the case where the machines go quiet. We would prefer not to be drawn on how often we expect to use it.”

The question a tenants' meeting would reportedly ask is the one the draft does not answer. The tenant next door is a business that can move its work to another country at an hour's notice, and is paid by the electricity grid for its willingness to do exactly that. Flexibility sold upstream as a grid service arrives downstream as a stairwell in November.

The draft handles this with a notice period. An operator planning a prolonged reduction in load would have to inform the utility in advance, in the way a water company announces its intention to dig up a road. Nobody at the table seems entirely comfortable with what that sentence describes: a maintenance window for somebody else's computers, which four hundred households would be expected to plan around, like a lift out of service.

Price is the other open item. Residents would want a tariff reflecting their place in the queue — heat that reached the supplier for nothing should not arrive at a radiator priced as heat. The utility's drafted answer is that the alternative is gas, and that gas comes with its own list of people you depend on, cannot see, and have never been introduced to.

None of this is signed, and the contract may never exist in this form. But the pipe would be short, the heat is real and is currently thrown away, and the only genuinely new element is the dependency: a block of flats whose comfort would be tied, for the first time, to demand for computing that its residents will never use and cannot observe.