Data centers can replace existing heating plants in a district heating system if the right cooling technology is used (liquid-cooled data centers). The goal is to use excess heat that does not need heat pumps and repurpose it in a district heating network. A testbed has been created to support the technological development of liquid-cooled data centers.
The project aims to demonstrate the opportunities and obstacles that exist to switch from air cooling to liquid cooling of data centers, with it being able to allow data centers to constitute as a virtual heating plant in the district heating system. The specific cost of liquid cooling is normally more expensive compared to traditional air cooling, by selling the excess heat as district heating there are opportunities to repay that additional cost within a few years.
Data collection from existing data centers and heat production plants shows that the specific power intensity of a data center can in some cases correspond to a heating plant a district heating system. With today's development towards more powerful servers and the use of GPUs for HPC calculations, the power intensity will increase and make data centers more competitive and attractive as heat sources. An evaluation of different possibilities for connections of the data center to the district heating network shows that the data center can be connected as a traditional heat production facility. Where water from the return line is extracted and heated to be returned to the supply line, to achieve the desired temperature, the flow through the plant is adjusted.
At the ICE data center research facility (RISE), a testbed has been established that enables the evaluation and development of liquid cooling techniques and products. The testbed is connected to the property's domestic hot water and hot water circulation system in the same way as a possible heat production plant. The highest temperature reached on the excess heat is 72 ° C in a lab test, it is suitable for a 4th generation or a low-temperature district heating system. To upgrade to high-temperature district heating, only a small heat pump stage is needed, compared to lifting from 35 ° C, which is normal for an air-cooled data center.
To enhance the use of liquid cooling in data centers for heat recovery the biggest obstacles are; the additional cost of more expensive technology, knowledge of the properties of the technology, lack of cooperation models, and division of ownership responsibility between the data center owner and the recipient of the surplus heat.
Mattias Vesterlund e-mail
- Heating and cooling
- Technical solutions