In our previous article on liquid cooling in data centers, we emphasised the vital role of data centers in the infrastructure of the modern world. In this article, we turn our focus to waste heat recovery systems in data centers.
Similar to a laptop gradually heating up as it used, data centers consume a significant amount of electricity and generate an immense amount of heat that is often treated as waste and then released into the atmosphere. We wanted to take this opportunity to talk about what fire engineering considerations arise when data centers implement waste heat recovery systems.
Waste heat recovery systems are by no means novel and work on the simple philosophy that waste heat captured in one part of the facility can be reused in other applications. Waste heat recovery has been used in electronics, industrial processes and air conditioning and can be similarly fundamental to data center operations. Typically, waste heat from a data center is released into the atmosphere. With waste heat recovery systems, however, waste heat can be used to provide heat to neighbouring homes and businesses.
For example, where data centers are connected to district heating network, water from the local district heat network is “cycled” (through exchangers) into the data centers to cool equipment, and the heated water is cycled back out into the district system. This helps reduce the energy demands of surrounding communities and is an excellent example of a sustainable heating solution for the community.
These systems are already being installed in Europe, such as a Google data center in Hamina, Finland. At the time of launch, the data center was estimated to provide 80% of the heat used to warm homes and offices in Hamina. Other examples include a Microsoft data center in the suburbs of Helsinki which heats the homes of a quarter of a million people, an Amazon Web Services (AWS) data center in Tallaght, South Dublin, and a similar example is being built at Old Oak Common in London.
Greater attention is being drawn to the energy demands of data centers and, with the energy transition a growing priority among policymakers and investors, businesses are coming under greater scrutiny to meet their commitments to net zero carbon. Waste heat recovery systems are thus becoming an important part of offsetting data centers’ impact on the environment.
In Germany, for example, a new Energy Efficiency Act has made waste heat recovery systems a requirement for all new facilities, with the aim of reusing 20% of their heat by 2028. The UK’s Climate Change Committee (CCC) has similarly emphasised the extent to which heat recovery systems could be transformative for UK heat and its climate mission. With an estimated 2% of the country’s current heat needs being supplied by piped heat networks, the CCC have calculated this could increase by up to 18% by 2050.
While it is evident that heat recovery systems can benefit the sustainability of data center operations, there are some key fire safety challenges that should be considered. Integrating additional systems into a data center requires spatial planning, additional equipment and fire risk assessment of such systems, and most importantly, the facility now becomes a two-fold part of critical infrastructure: one for data and internet services, and the other one for waste heat / energy recovery. The service loss of a data center would now impact both functions and, as such, the need to ensure reliability and resilience (including from a fire safety perspective) is of vital importance.
It is essential that options for utilising waste heat recovery systems are part of the initial planning stage of the design of a new data center. Operators of existing data center facilities should also consider business and sustainability opportunities arising from retrofitting such systems and equally the fire safety risks arising from such installations.
It is likely that the heat recovery solutions will become integrated in the construction of many data centers in the future. Data centers, therefore, can be more than just essential infrastructure, but a driving force in a more sustainable future for local communities, too.
If you are working on a data center project or using waste heat recovery and need specialist fire safety input, we would be happy to help. Please get in touch with us at info@joule-group.com
Sources
Data Centre Review - Making the most of data centre waste heat
Dgtl Infra - Data Centre Fires: A Detailed Breakdown with 22 Examples
Fortum - Data centres and district heating: a perfect match
Local community buildings in Ireland to be heated by Amazon data center
Waste Heat From Google Data Center To Warm A Town In Finland