A UK energy network operator is looking to heat residential homes with on-site compute via immersion-cooled Raspberry Pi clusters.

Energy network operator UK Power Networks (UKPN) has announced a new initiative to help those struggling with energy bills by providing low-cost on-site heat generation via ‘digital boilers’.

The SHIELD system (Smart Heat and Intelligent Energy in Low-income Districts) works by installing and managing solar panels, battery storage, and Thermify’s HeatHub in people’s homes.

The HeatHub is a mini data center, about the size of a large heat pump, which captures and stores the excess heat it generates, making it available for customers to use for heating their homes.

The company has partnered with Termify, Power Circle Projects, Eastlight Community Homes, and Essex Community Energy Community Interest Company to support the rollout. Solar and battery systems will be installed in all participating households, with HeatHub systems installed in a third of them.

At least one SHIELD system with a HeatHub has been deployed so far, with a 40 percent reduction in heating bills as a result. Resident Terry Bridges said: “The heat hub has made a real difference to our comfort and energy costs. Our home feels warm throughout – especially in the bedroom, which was always hardest to heat.”

With support from Ofgem’s Strategic Innovation Fund, up to 300 social tenants will participate in a trial of SHIELD across the East and South East of England over the next four years. This phase of the project will collect evidence to support the scaling of SHIELD, with the aim of deploying 100,000 systems annually by 2030.

Luca Grella, head of Innovation at UK Power Networks, said: “SHIELD is a transformative initiative that empowers households to control their energy costs and support the country’s climate goals. By providing innovative technologies at no cost, we are making a real difference for some of the most vulnerable members of our community.”

UK Power Networks is the UK’s largest distribution network operator, operating power infrastructure to a quarter of the UK’s population around the southeast of England. Previously part of EDF, the company became UKPN after EDF Energy Networks was sold to Hong Kong’s Cheung Kong Holdings in 2010.

London-based Thermify aims to ‘replace gas boilers in homes and generate new revenue from cloud computing,’ creating heat for residential homes to utilize. First launched around 2021, the firm aims to create a network of distributed nodes that can run workloads for its cloud customers.

The company told the Reg that the HeatHub is equipped with 500 Raspberry Pi Compute Modules, either the CM4 or CM5, submerged in oil. A dedicated network connection is also installed.

Low-income tenants will pay a monthly charge of £5.60 ($7.52), and participating tenants could reportedly reduce their energy bills by 20 to 40 percent.

Charlie Edgar, who has overseen the SHIELD work on behalf of Eastlight Community Homes, added: “The pilot results for this innovative solution are very encouraging and we’re excited to see it being trialled in hundreds more homes. We can see the potential to provide reliable heating at a predictable low cost, empowering families to maintain a comfortable living environment without the stress of rising energy bills.”

Thermify is not the first company to try heating homes with the waste energy generated by compute processing.

French company Qarnot raised €35 million ($38m) in January 2023 to expand the production of its digital boilers that heat water using waste heat from servers installed on-site. Qarnot was founded in 2010 and has been offering this service since 2015 – though it has also been targeting larger deployments in recent years. Another French company, Hestiia, has its own digital boiler offering.

Cloud service provider Civo announced it was partnering with Heata to provide hot water to UK homes via heat from on-site servers connected to domestic heating systems. Civo also joined forces with Deep Green last year to provide cloud services on data centers that heat swimming pools.

Not every company that has attempted to bring this alternative heating method to the masses has seen success, however. Other companies that have now exited the field include Germany’s Cloud&Heat, which now offers efficient Edge data centers instead of digital boilers; Dutch startup Nerdalize, and New York-based Exergy.

UKPN is also working on a larger data center-focused district heating initiative – called Hot Chips – that aims to develop a framework that incentivises collaboration between electricity network operators, heat network providers, and data centers.