Data centres enable everything we do online, from powering the Internet to making digital communication and connection possible. But as technology develops, society has become hungrier for access to data, resulting in data centres craving more power.
As a building use in the built environment, data centres have a comparable high energy and produce large amounts of excess heat. Across the sector, new technologies are constantly being developed to minimise heat waste and maximise solutions for surplus heat. Over the last few years, cooling techniques have been a primary focus for operators to cut back on carbon, alongside regional regulations halting developments in efforts to prioritise decarbonisation – but there is untapped potential in other areas.
“Heat decarbonisation in buildings is a huge challenge, and one that is often fundamentally misunderstood – heat networks are the only internationally proven route for decarbonising heat at scale, yet most people don’t know what they are,” said Matthew Basnett, Heat Network Policy Lead, Association for Decentralised Energy (ADE).
We’ve observed how effective this can be from Deep Green’s recent initiative of providing free heat for energy-intensive organisations like leisure centres, consequently receiving free cooling. This resourcefulness amplifies the benefits data centres can have on local communities and wider societies.
Whether its architectural alterations in the design phase, or government-funded plans to encourage efficient engineering, as regulatory deadlines for carbon neutrality creep ever closer, progressive changes for a sustainable future may seem closer than we think.
To get further insight into heat reuse and what’s next for the industry, we speak to Alex Soto, Associate Director & Head of Sustainability, studioNWA; Salih Toyran, Director, Mission Critical Business Lead, chapmanbdsp; and Mohammad Royapoor, Head of R&D, Red Engineering.
Alex Soto, Associate Director & Head of Sustainability, studioNWA
It is encouraging to see data centres integrated into community infrastructure, and their synergy put to work to help decarbonise domestic heating in urban settings. A welcomed example is the recent rollout of a waste heat recovery scheme in west London, at Old Oak and Park Royal – OPDC’s new development area. Excess heat from a cluster of data centres will be captured and distributed to a network set to provide low carbon heat to 10,000 homes and a hospital: the first in its kind in the UK, setting a blueprint for similar projects in the future.
From the architectural design perspective, a few space planning implications are to be considered when incorporating waste heat recovery systems into data centre design. Plant rooms for pumps and piping need to be provided, without compromising prime space allocated for IT equipment that could affect IT capacity, when integrated within the building footprint in compact sites.
These rooms need to be easily accessible for maintenance and compliant with building regulations and fire safety. Tap off points are often required at the permitter of the site to maintain site security. Early engagement with M&E engineers is essential to ensure the design delivers an efficient layout and optimal adjacencies to cooling systems to capture the excess heat at its source.
Mohammad Royapoor, Head of R&D, Red Engineering
In their more refined moments and when dealing with system level problems, engineers are often reminded of the Laws of Thermodynamics. These three laws are among the only time independent sets of guidelines in natural sciences align. The more intuitive of all is the first law: the conservation of energy. When combined with the second law, it follows that the universe holds a finite amount of energy. The heat that data centres generate is not waste heat but a part of this finite source.
At RED Engineering, we prefer to refer to it as surplus (rather than waste) heat. The progressive incorporation of ‘recycling’ and ‘reusing’ into both material and energy flows plays a pivotal role on our journey to carbon neutrality. We have conducted techno-economic research into two main catalogues of solutions for surplus heat: utilisation from data centres and other industrial processes.
First is to export the heat to external consumers. As yet, there are a limited number of these installations in operation, with the majority in Nordic countries. The techno-economics of heat export from data centres will be enhanced by the move away from air cooling and the adoption of liquid cooling.
An accurate annual profile of surplus heat from a data centre and heat demand from nearby consumers are critical to successful execution of this option.
The arrival of the latest 5G district energy systems (running typically at around 28ºC) will also be a boost to viability of data centre heat export. Equally, the pressure from the regulator to limit data centre heat rejection. This solution could be particularly effective for commercial or residential buildings around data centres which rely on fossil fuel for space heating. It could also aid nearby communities to overcome environmental and social challenges such as air pollution and fuel poverty.
A second solution RED Engineering has explored is data hall heat recovery for internal use. A novel approach we looked at was heating the standby generators jackets (often referred to as heat soaking). In one application, we observed that this solution can offer an annual carbon saving of 50 tonnes for a 32MW data centre when benchmarked against direct electric heating of the engines in the relatively moderate climate of London. Each application is of course unique.
Consequently, that is why we have a broad programme of ongoing R&D in which we closely examine the thermal management of microgrids – from surplus heat of the data centre halls to the steam generated using onsite turbines and engines that is then used to drive absorption or steam driven chillers and finally heat export to district energy systems. We realise that we live in a world of finite energy where every unit of it needs to be utilised intelligently and sustainably.
Salih Toyran, Director, Mission Critical Business Lead, chapmanbdsp
With more than 25 years’ experience within the mission critical industry and over 30 years within the engineering design and construction sector, I have witnessed that in our industry, waste heat hasn’t been considered for a long time and that is a great shame. It has meant that huge amounts of waste heat have been extracted into the atmosphere.
Data centres are after all consuming 3-3.5% of the world’s energy. It’s not surprising therefore that many European countries, especially the Nordics have started to engage with this issue and certainly earlier than the UK. This is an obvious move given data centres are generating such a large heat output.
The UK has for launched an initiative in this area at the end of 2023, with a funds of around £65 million available for infrastructure relating to the waste heat from data centres. While there have previously been inroads made by the private sector, this is the first solid step from the public sector in terms of readiness to collect all this waste heat. It needs to be driven by legislation and the government should come up with a plan for serious targets for reusing heat from data centres.
In Germany, they have already set targets for 2026 whereby a minimum of 10% of waste heat should be given back to the community, with that figure rising to 20% by 2028. I would like to see this enforcement for the UK, as this will drive further discussion about how to collect the heat and what the criteria to collect the heat is, as well as what technology is required – as has happened in Germany.
From the data centre side, the infrastructure is already in place for a few areas in London, such as Hammersmith, Fulham and Brent. With this government funding, it will enable the infrastructure like the pipework to be created to link up with local communities, along with the potential to generate enough energy for 250,000 homes which could be sold at a cheaper price. If you consider that possibility, it really is a no brainer. It’s not just national government though, everybody has to share this drive towards the next step in heat reuse from contractors and designers to local authorities and manufacturers.
