15 March 2016
Due to the accelerating use of the Internet and network-based services, large data centres have become very
important. There are currently over three million data centres globally, and Information and Communications
Technology (ICT) consumes up to 10 % of the world’s electricity. Most computer cooling systems do not have any heat recovery system. However, there is a strong trend towards green data centres with minimum primary energy use and low greenhouse gas emissions. An excellent example of green ICT is the supercomputer centre at the Norwegian University of Science and Technology (NTNU) in Trondheim, Norway. The excess heat from the combined liquid chiller and high-temperature heat pump system is utilized in the local district heating system at the campus, thus reducing the net primary energy use to a very low level.