Passive cooling
for long operating hours
and continuous heat loads.
Cooling Data Centers and Server Rooms with Geo-HEP Systems
Efficiently dissipating sustained heat loads—
using the mountains as a natural heat sink.
Data centers and server rooms continuously generate heat over many hours of operation. These thermal loads must be reliably dissipated from the technical infrastructure.
Geo-HEP uses the subsurface as a natural heat sink for this purpose. Under suitable conditions, a significant portion of the cooling can be achieved passively, without the need for a conventional chiller to operate continuously.
Whether and to what extent Geo-HEP can be used depends on the actual cooling demand, the required temperatures, the existing plant equipment, and the geological and hydrogeological conditions of the site.
The Geo-HEP high-performance energy pile uses the mountains or the subsoil as a natural thermal sink for this purpose. Under suitable conditions, cooling can occur passively without the need for a conventional chiller to operate continuously.
Whether and to what extent a Geo-HEP high-performance energy pile can be used depends on the actual cooling demand, the required temperatures, the existing system infrastructure, and the geological and hydrogeological conditions of the site.
The System Principle at a Glance
This is how the Geo-HEP high-performance energy pile dissipates heat from the data center
In the data center, the cooling system absorbs the heat generated by servers and technical infrastructure. This heat is transported via a technical cooling loop to the Geo-HEP high-performance energy pile and released into the ground. The cooled medium is then returned to the server room.
Take in warm air
The air heated by servers and technical components is drawn in by the cooling system.
Transferring heat to the cooling circuit
The heat is transferred to the circulating heat transfer fluid in the technical cooling circuit and transported to the Geo-HEP system.
Buffer thermal loads and dissipate heat
In high-performance energy piles, the integrated thermal storage mass can absorb short-term load peaks. The heat is then transferred to the surrounding ground via the pile's surface.
Recirculate Cooled Air
After heat is dissipated, the cooling circuit returns to a lower temperature level. The room air or supply air is cooled using the cooling system and recirculated back to the server area.
Geo-HEP operates as a closed heat exchange system.
Groundwater is neither extracted nor incorporated into the system's circuit.
Why Geo-HEP Systems Are Attractive for Data Centers
Data centers have an application profile that is well-suited for geothermal cooling systems: cooling energy is required for many hours each year, while thermal loads can fluctuate throughout the day and during operations.
Making Efficient Use of High Operating Hours
At appropriate system temperatures, the Geo-HEP system can provide passive cooling. Electrical energy is primarily required for circulation pumps and for measurement, control, and regulation technology.
Especially when annual operating hours are high, the low auxiliary power consumption can make a significant contribution to energy efficiency and cost-effectiveness. The actual benefit compared to an existing or planned cooling system is determined on a project-by-project basis.
Buffering Thermal Load Peaks
The integrated thermal storage mass of the high-performance energy piles can absorb and buffer short-term load peaks. The heat is then transferred to the surrounding ground via the pile surface.
The significance of this buffering function in a specific data center depends on the load profile and the system’s design.
Making Efficient Use of the Subsoil
High-performance energy piles provide a large heat exchange surface area and allow for a compact system layout.
This can be particularly advantageous at sites where only limited space is available for geothermal development. The number and arrangement of the high-performance energy piles are determined based on the cooling demand as well as the spatial and geological conditions of the site.
Geology and groundwater determine performance
The ability of the subsurface to absorb and transport heat is crucial for the design of passive cooling.
In addition to the structure, stratification, thermal conductivity, and heat storage capacity of the subsurface, hydrogeological conditions therefore also play an important role.
Integrating the Geo-HEP System into the Cooling Design
Geo-HEP can be evaluated for both new data centers and the retrofitting of existing cooling systems.
Key factors for integration include the existing system hydraulics, the required temperatures, the actual load profile, operating hours, and technical interfaces.
Whether the Geo-HEP system replaces existing cooling technology, supplements it, or is operated in conjunction with other cooling systems is determined as part of the project-specific planning.
Considering Heating and Cooling as Part of an Overall Concept
Where there is a high demand for cooling but heat is also required—either simultaneously or at different times—Geo-HEP can also be considered as part of a combined energy supply concept. In heating mode, the geothermal system can serve as a heat source for a heat pump. The specific application depends on the project’s individual heating and cooling profile.
Incorporating Redundancy and Cooling Reserve into the Cooling Design
For data centers, in addition to regular cooling operations, it is also necessary to consider how heat dissipation can be maintained during maintenance, malfunctions, or the failure of individual components. Depending on the required level of availability, redundant components or additional cooling paths are provided for this purpose.
Geo-HEP can be incorporated into this overall planning.
Combining the Geo-HEP High-Performance Energy Pile and Seasonal Storage
The Geo-HEP seasonal storage system is currently under development. Its potential use as a cooling reserve for data centers should therefore be viewed as a conceptual approach and must be technically validated and designed for each individual project. Key factors would include, among others, the required cooling capacity, the desired backup duration, the temperature level, the charging strategy, the hydraulic integration, and the required redundancy and availability concept.
A thermal storage system does not, therefore, automatically replace the comprehensive redundancy planning of a data center. However, it could potentially serve as an additional component within a coordinated cooling and failure-contingency strategy.
Normal Operation via the High-Performance Energy Piles
During regular operation, the high-performance energy piles transfer heat to the ground and serve as the heat sink for the cooling circuit.
Targeted cold storage
A seasonal storage system could be charged to a low temperature level suitable for the respective cooling concept and maintained as an additional thermal reserve.
Activating
the reserve as neededIn the event of a malfunction, maintenance, or a temporary interruption of a regular cooling path, the seasonal storage system—depending on the hydraulics and control system—could be temporarily integrated into the cooling circuit. It would also be conceivable to use high-performance energy piles and storage systems together for a limited period to dissipate an increased thermal load.
Such a storage system could thus provide a thermal bridge until a redundant cooling path takes over or the regular cooling system is fully operational again. This requires that the pumps, heat exchangers, control devices, and room-side cooling necessary for the cooling circuit remain functional and are adequately protected.
Is Geo-HEP suitable for your data center?
For an initial project evaluation, we focus in particular on:
- Cooling capacity and thermal load profile
- Required system and cooling temperatures
- Annual operating hours
- Existing or planned cooling technology and hydraulic interfaces
- Requirements for availability, redundancy, and potential bridging times
- Available space at the site
- Geological and hydrogeological conditions
- Options for the future integration of thermal storage systems
Based on this information, it is possible to assess whether passive cooling using Geo-HEP can, in principle, be effectively implemented, what role the system could play within the cooling concept, and what a detailed technical design would need to look like.