The combination of data centers and heat pumps stands at the center of a key problem within modern data centers. As these structures are increasingly in charge of powering the global economic system, the strategies towards achieving energy efficiency in their operation have become a crucial issue.
As such, operators are on the lookout for a sustainable model that guarantees correct data center heat load as well as energy efficiency and sustainability. Today, the most encouraging option involves the combination of data centers and heat pumps that allow for heat waste recovery, hyper-efficient hardware, and the use of clean and renewable energies.
At Araner, we want to focus on how heat pumps are enabling a shift of paradigms that include the generation of circular, closed-loop models with no waste. For instance, data centers and heat pumps are being successfully paired with district heating initiatives, able to provide heating through reusing waste energy. Let’s see how.
The effort towards efficiency in data centers
Much is being discussed about the present and future of data center technologies, as the issue of energy efficiency in these systems is understood as a key matter in global development.
The truth is that data centers today are significant contributors to carbon emissions and their need for installed cooling systems, a major source of energy consumption. As such, the operation of data centers presents energy demand on two fronts: they use electric power to make hardware work and perform; and use energy for data center cooling processes, ensuring technological equipment can operate safely and reliably without overheating.
In fact, as per ASHRAE (American Society of Heating and Air-Conditioning Engineers) guidelines, data center recommended temperature values should be kept between 18°C up to 27°C. This translates into a significant effort in devising efficient cooling structures for data centers.
At the same time, the operation of data centers also involves the generation of low-grade heat energy. In fact, it’s estimated that up to 98% of the electricity consumed by data centers is then discarded as low-grade heat energy. Other data, such as the one published in the white paper ‘Utilization of Waste Heat in the Data Center’, provides a look at German data centers, where more than 13 billion kilowatt hours (kWh) of electricity per year are currently being converted into heat, with the majority of this figure being released unused into the environment.
In a context where energy efficiency is not only more economically-savvy but also encouraged, and even mandatory, this issue must be addressed. This is particularly true considering demand for digital applications (and, consequently, for data center technologies) continues growing unstoppably.
In such a context, organizations such as the Green Grid and the U.S. Environmental Protection Agency (EPA) have established efficiency standards for data centers. These include important measures such as Power Usage Effectiveness (PUE) and Water Usage Effectiveness (WUE).
A number of solutions are being devised to address this problem. On the one hand, some enterprises involve the reduction of energy use through energy-efficient computer systems.
On the other hand, the focus on waste heat recovery and its reuse through the combination of data centers and heat pumps is at the center of many initiatives.
How data centers and heat pumps combine
The challenge of reusing waste heat from data centers lies at the type of heat energy that is released by data centers: excess heat generated by servers is low-grade and low temperature.
This is where heat pumps come in: the working principle of heat pumps is to absorb thermal energy from lower temperature sources and transfer it to a higher temperature environment. In fact, industrial heat pumps are able to amplify temperatures to 60°C or higher, while multi-stage heat pumps can achieve temperature values of 150°C or higher.
In other words, they’re able to capture and recycle excess heat generated by data centers, and transfer it to a variety of systems where it can be then converted into useful heat energy. From local communities and other facilities (including farming spaces) that are benefited through district heating initiatives, to applications in the industry and more.
Additionally, successful initiatives are also employing the possibility of incorporating sustainable and renewable energies to operate heat pumps facilities. This includes the use of seawater heat pumps.
The efficiency of data centers and heat pumps
The quest to achieve energy efficiency on data center heat generation and waste energy recovery is framed within a larger context of global efforts towards sustainability. Within this scenario, a number of initiatives and debates have arised recently, which aim to consider what is the right solution towards energy efficiency. Such is the case of deliberations looking at employing combined heat and power or heat pumps to achieve maximum efficiency.
In such a context, the truth often lies in looking at each project’s needs, potential and limitations. At the same time, opting for data centers and heat pumps has remained a solid option for many projects due to this system’s heat enhancement capacities and their outstanding efficiencies.
Heat pump efficiencies are measured by the Coefficient of Performance or COP, defined as the ratio of the heat energy transferred from a cold source to a hot reservoir. In other words, it is the ratio that compares desired output to the required input. The higher the COP, the more efficient the heat energy system. Industrial heat pumps are known for their extreme efficiencies, reaching COP values of 3.0 to 6.0. This leads to an extraordinary potential in terms of data center heat load recoveries. For instance, a data center paired with a heat pump that presents a COP of 5.0 and operating on electricity costs at $0.10 per kWh would be able to recover heat and turn it into high-value thermal energy for $0.0083 per kWh, as calculated by the Data Center Knowledge online publications.
At Araner, we provide solutions for data center cooling and heat pumps, and are at the forefront of helping projects achieve maximum efficiency in their operation. This is why we’re also involved in generating sustainable, closed-loop models that make the most of data center excess heat to benefit district heating initiatives.
As such, we put state-of-the-art heating technology and engineering expertise at the hands of our clients, including options such as Thermal Energy Storage (TES) tanks and Modular and fully-integrated cooling plants.
Want to learn more? Get in touch with us and find out how we can help you.