When Giles Gibson turns on the hot water tap in his south-east London home, the heat comes from a compact computer server attached to his hot water tank rather than a standard gas boiler. Supplied by Surrey-based startup heata, the device processes cloud computing tasks for corporate clients while transferring excess heat directly into the cylinder. Gibson estimates the system has reduced his hot water bills by £10 to £15 a month over the past year.
Large datacentres worldwide generate immense waste heat, but home-based units aim to recycle that energy on a domestic scale. Heata’s unit, which packs the computing power of roughly eight laptops, is retrofitted to existing vented water cylinders using thermal paste and requires no new plumbing. The company pays for the server’s electricity while homeowners provide a fibre broadband connection. Heata aims to cover about 80 percent of a household’s hot water needs, leaving traditional boilers to assist only during peak demands like taking a bath.
The technology is currently installed in 100 homes across the UK, with 3,000 people on a waiting list and hundreds more installations planned for next year. However, the current model only works with vented water cylinders, though a version for unvented cylinders is in development.
Meanwhile, alternative domestic heating concepts are also emerging. In Essex, two households are testing a unit called HeatHub, developed by Welsh company thermify. The freezer-sized system houses nearly 500 matchbox-sized Raspberry Pi computers submerged in mineral oil, which transfers heat to radiators through a heat exchanger. Thermify plans to offer these units for a monthly fee of £90 under 10-year contracts, claiming potential long-term bill savings compared to standard gas boilers or heat pumps.