Jim Weynand, EVP, Business Development at GRC, discusses how data centres are using innovative techniques to capitalise on excess thermal energy – creating more opportunities for sustainable development.
Data centres are notorious for exuding mass amounts of energy and heat. Maintaining the operation of servers demands a massive amount of power, which generates a lot of heat energy. While this can inherently damage the environment if left unchecked, the excess presents a powerful opportunity in the form of data centre heat reuse.
This article is a guide to the possibilities of heat reuse, exploring how data centre operators can capitalise on excess thermal energy, leading a revolutionary charge towards renewable energy through data centre infrastructure.
Heat reuse – The basics
Let’s turn that waste heat into something useful. Instead of expelling heat from a data centre into the environment, which is unsustainable for most settings, heat reuse repurposes that energy. Rather, the technology uses that energy for more practical uses, ranging from reutilising the heat within the data centre to heating a local swimming pool.
No new data centres
Greater emphasis on heat reuse applications is pressing – compute demands on data centres continue to surge despite increased regulation blocking the construction of new facilities. Europe is cracking down on the data centre market with sustainability-charged restrictions.
Reducing emissions is the priority laid out by the 2020 Paris Agreement and the EU has laid out trackable targets for nations under the NDC Registry. This public record requires countries to cut emissions in half by 2030.
In 2022, the Netherlands placed a temporary ban on new data centres. Facilities larger than 10 hectares that consume more than 70MW have been heavily restricted in the region as more and more countries like Ireland and Germany push back on hyperscalers.
Making heat reuse work
Building new data centres isn’t the answer to heat reuse – nor does it have to be. Modern data centres are primed for infrastructural changes. Exploring sustainable server cooling solutions is a big first step in shifting data centre heat output.
Air-vented cooling is the traditional method for maintaining data centres, regulating the temperature of server equipment so that it can operate efficiently. The waste heat from data centres, and the conventional cooling methods that expel it, are huge contributors to high emissions. Up to 50% of traditional data centres’ energy is dedicated to air cooling.
Upgrading facility cooling systems can reduce a data centre’s carbon footprint. This is a fast-growing market, as more operators seek bespoke solutions to slot into their data centre’s infrastructure.
Liquid immersion cooling is an alternative to traditional cooling, which has picked up momentum, with the market projected to grow by 22% by 2028. Immersing server hardware in liquid coolant prevents equipment from reaching higher temperatures and can be extracted for productive applications instead.
Data centre densities will rise significantly over the next few years and the thermal design power (TDPs) for chips will continue to increase as well. Data centre owners can future-proof against rising heat requirements through their cooling solutions. There are immersion cooling solutions available that can handle the increased heat of these chips up to 400W and are on track to handle beyond 1000W.
Most significant heat reuse benefits
Powering auxiliary facility systems
Keep your servers cool and your staff warm.
By transferring excess to a heat exchanger, captured energy can warm office areas within a data centre. This process helps cut costs for additional heating systems and your facility staff won’t need blankets come winter time.
The savings don’t stop at radiators, either. Immersion cooling directly utilises captured heat to reduce the need for additional hot water heating and mechanical systems. It leverages excess data centre heat enabling them to offset historically high energy consumption, bringing the industry more in line with new regulations.
Redirecting to district heating systems
Providing free heating to district energy systems local to a data centre has become the industry’s sustainable flagship for goodwill gestures. This process involves connecting data centres to external systems, distributing recycled heat to homes and businesses for hot water and heating.
Extending that green initiative further, there have been cases in which data centres have redirected captured heat towards greenhouses and farms. This initiative significantly reduces the carbon impact of local areas by supporting nearby agricultural efforts with reused heat.
It is worth noting that integrating with district heating systems presents unique challenges for traditional data centres. Air-based cooling systems can lose efficiency when transferring heat into water for local usage. This is a massive driver in the sector’s push for liquid cooling adoption.
Deliver at any scale
Implementing heat reuse processes isn’t limited to hyperscale facilities, with operators at any level of the data centre chain able to make a difference with the server-generated heat.
Data closets – Every little helps. Using heat reuse can save on OpEx and the heat from small office server rooms can warm nearby areas incurring significant savings on heating.
Decentralised data centres – Small-scale data centres in densely populated areas are designed to reduce end-user latency. They boost your online experience and the heat produced can be transferred to adjacent buildings to warm them.
Private data centres – Data centres within organisations have much more flexibility with infrastructural changes than smaller data centres. It means enterprises can tailor heat reuse solutions to suit their needs and requirements. Owners can partner with nearby enterprises to redirect heat energy to external facilities or recycle the heat within their data centre.
The time for change is now
Heat reuse has become a key initiative in the push for green data centre solutions. Norway has demanded formal requirements for data centres to make better use of excess heat. Currently, this only requires a report on sustainable efforts made by data centre operators, but may eventually lead to stricter heat reuse requirements. As the path towards 2030’s emission goals continues, expect other nations to follow a similar line of thought.
The heat reuse solutions, such as server cooling hardware adjustments, are not theoretical. Data centres can make the switch now, not only to go green but also to generate massive savings through heat reuse. The cost benefits for CapEx and OpEx are abundant for heat reuse – making infrastructural changes to facilitate it is substantially cheaper than building a data centre from scratch. It’ll also bring facilities more in line with current and future ESG regulations, which is far easier than getting permission for a new data centre.
