Learn how nLighten’s Integrated CFE Score incorporates heat recovery to enhance data center efficiency and sustainability.
Data centers are the backbone of our digital infrastructure, crucial for storing, processing, and managing the ever-increasing amounts of information generated by the digital world. Consequently, the data center industry has experienced significant growth in recent years. However, this expansion comes with notable environmental implications.1 According to the EU Science Hub, data centers currently account for about 1.4-1.6% of total EU electricity consumption, a figure that is expected to continue rising.2
In response, the industry is currently experiencing a paradigm shift towards sustainability. Innovative strategies and techniques are emerging to enhance energy efficiency, integrate renewable energy sources, reduce carbon emissions, and implement advanced technologies. One particularly promising approach is the recovery of electrical energy in the form of heat, which holds significant potential not only for data centers, but also for their surrounding communities, with applications ranging from heating buildings to supporting industrial processes.3
Our Carbon-Free Energy (CFE) Study, developed in collaboration with the Eni Enrico Mattei Foundation (FEEM), underscores how integrating heat recovery into the CFE metric quantifies the emissions reduction it can bring to other connected energy systems. By understanding the origins of this heat and exploring creative ways to repurpose it, data centers can become a lever to energy conservation and lower emissions in their surrounding communities.
Table of Contents
- Understanding Excess Heat in Data Centers and Effective Management Strategies
- The Benefits of Implementing Heat Recovery
- Incorporating Heat Recovery into Sustainability Metrics
Understanding Excess Heat in Data Centers and Effective Management Strategies
Once one has adopted an integrated view of the Data Center within its surrounding community, ensuring the highest possible proportion of recovered heat is essential for improving energy efficiency of the system. The system, as we call it, is the data center and all other connected energy systems.
The higher aggregate efficiency, caused through recovery and re-use of energy between users, is called “Sector Coupling”. In cases where the recovered heat energy offsets a carbon intensive heat source such as gas, oil or coal, a system emissions reduction is achieved – additional to a system efficiency increase.
The heat primarily originates from compute loads housed within these facilities such as servers, GPUs and networking equipment. These systems perform intensive computational tasks that as a biproduct convert electricity to heat. To maintain stable operating conditions, data centers implement cooling systems, including air conditioning, liquid cooling and airflow management.
Traditionally, these cooling mechanisms expel the heat into the environment at temperatures too low to be used for heating purposes. However, modern Data Center Designs capture, condition and transport the server heat to other energy users. These systems typically involve simple components such as heat exchangers and heat pumps, which are selected to provide compatible temperatures to both the data center operation and heat users. For example, the recovered heat can be used for district heating, providing heating to nearby residential or commercial buildings, or it can be redirected to power industrial processes.4
The Benefits of Implementing Heat Recovery
- Enhanced Energy Efficiency: By recovering electrical energy converted to heat by server loads and using this for heating buildings or processes, data centers can markedly improve the energy efficiency of the combined system. Via Sector Coupling the data center becomes a means to lower the aggregate energy consumption of the community.
- Emissions Reduction: By providing communities with recovered heat, data centers offset and reduce reliance on conventional, more carbon intensive, energy sources. This provides a path to emissions reduction, improving overall community sustainability and aiding the energy transition.
Incorporating Heat Recovery into Sustainability Metrics
Incorporating heat recovery into sustainability metrics represents a significant advancement in the holistic assessment of environmental impact, particularly within energy-intensive sectors such as data centers. Traditional sustainability metrics have often focused exclusively on electricity consumption, overlooking the broader potential for energy efficiency and emission reduction through the integration of heat recovery.
The Integrated Carbon-Free Energy (CFE) Score exemplifies this approach. This metric expands the conventional CFE indicators to include both electricity and heat, allowing for a more accurate representation of a data center’s contribution to environmental sustainability. By factoring in heat recovery, the Integrated CFE Score highlights the positive impact of sector-coupled data centers on local energy infrastructures.
Through this innovative approach, heat recovery is recognized not merely as an add-on but as a critical component of sustainability strategies, driving progress toward a carbon-free future.
For more information contact our nLighten team.
[1] ING (OCT 2023): Data centre growth proves crucial in the shift towards a digital economy. Link:https://think.ing.com/articles/data-centre-growth-proves-crucial-in-shift-to-digital-economy/
[2] EU Science Hub (2023): The EU Code of Conduct for Data Centres – towards more innovative, sustainable and secure data centre facilities. Link: https://joint-research-centre.ec.europa.eu/jrc-news-and-updates/eu-code-conduct-data-centres-towards-more-innovative-sustainable-and-secure-data-centre-facilities-2023-09-05_en
[3] Jorge, Djessi (2024): The rise of sustainable data centers: Innovations driving change. Link: https://www.datacenterdynamics.com/en/opinions/the-rise-of-sustainable-data-centers-innovations-driving-change/
[4] Xiaolei Yuan et al. (2023): Waste heat recoveries in data centers: A review.Link: https://www.sciencedirect.com/science/article/pii/S1364032123006342
C. Montagud-Montalvá et al. (2023): Recovery of waste heat from data centres for decarbonisation of university campuses in a Mediterranean climate. Link: https://www.sciencedirect.com/science/article/pii/S0196890423005587 Tofani, Arianna (2022): A case study on the integration of excess heat from Data Centres in the Stockholm district heating system. Link: http://kth.diva-portal.org/smash/get/diva2:1723944/FULLTEXT01.pdf
