A London homeowner has reduced his hot water bills by up to £15 per month using a domestic datacentre system that converts computer processing heat into usable energy for his home.
Giles Gibson installed a server unit from Surrey-based company Heata last year, which attaches to his hot water cylinder and transfers heat generated by computer processing directly to his water supply. The system has cut his four-bedroom home’s hot water costs by between £10 and £15 monthly, equivalent to annual savings of £120 to £180.
“As soon as I read about it, I thought: ‘This is obvious – why wouldn’t you do this?'” Gibson said. “It just makes sense to take a computer out of a datacentre and to strap it next to your water tank and get free heat.”
Market expansion amid rising energy costs
The technology comes as domestic energy bills are scheduled to increase next month. Heata operates by sending processing jobs from commercial clients to servers installed in residential properties, with devices having the combined power of approximately eight laptops.
Charlie Beharrell, commercial director of Heata, said the company aims to provide about 80% of the heat needed for a home’s hot water. “The water in their hot water cylinder will effectively be heated by our server, and they might have to use the gas boiler for the peakier moments in the day, like when they have a bath,” he explained.
The system requires homes to have vented, unpressurised water cylinders, typically identifiable by blue insulation. Installation takes approximately two hours, with no cost to homeowners. Heata pays for the electricity used to run the server, while homeowners cover the fibre broadband connection required for operation.
Installation numbers and limitations
Heata’s units are currently installed in 100 homes, with 3,000 people on the waiting list. The company expects hundreds more installations next year. The system is not compatible with combi boilers, though a version for unvented cylinders is under development.
In Essex, a separate trial involves two households testing HeatHub units from Wales-based company Thermify. These freezer-sized units contain nearly 500 Raspberry Pi computers stored in mineral oil, which heats as the computers process tasks. The heated oil passes through a heat exchanger to warm water for radiators.
Travis Theune, Thermify’s chief executive, said the company plans to produce units sized for different properties, from microwave-sized units for flats to washing machine-sized systems for three to four-bedroom houses. The Thermify systems will cost homeowners £90 per month based on average-sized homes.
Both systems address the environmental impact of large-scale datacentres by recycling waste heat, though compatibility remains limited to specific property types. The technology represents an alternative approach to reducing heating costs, though uptake will depend on property suitability and consumer adoption rates in a market where property professionals are adapting to changing market conditions.
