Growing energy consumption is a global problem. The information and communications technology (ICT) industry is in a critical role as an enabler of energy savings in other sectors. However, the power consumption of the ICT sector also needs to be addressed, to contribute to the overall reduction of power consumption and carbon emissions. A new era has begun as the fifth generation (5G) mobile data connection rollouts are advancing globally and are expected to reach a 10% share of end-user devices and connections by 2023. The available references on energy consumption in global mobile networks are rather old and highly averaged – only estimates of energy consumption relative to data volumes are available. There is an information gap regarding the energy consumption of emerging 5G and advanced 4G technologies. Therefore, it has been difficult to understand the actual electricity consumption differences between generations and spatially aggregated electricity consumption once these generations are combined to offer capacity and coverage. This article fills this gap by providing a reference on the energy consumption of base transceiver stations for reported mobile data usage for different Radio Access Technologies; 3G, 4G and 5G respectively. To the best of our knowledge, there is no reference to scientific research on the comparison of energy intensity per square kilometer for 3G, 4G and 5G mobile radio technologies, using actual operator data. The objective of this research was to improve the understanding of the actual energy consumption of different Radio Access Technologies (RAT). The results also give insight to decision makers on when to modernize the operator radio access network. The article reports on the results of field measurements on data and visitor volumes and shares of different RATs. The research contains two statistical RAT combination cases, one representing the European average and the other Finnish mobile networks. The analyses were done for dense urban (DU) and suburban (SU) areas.

The use of mobile data has increased and will continue to increase in the future, because more data is moving to wireless networks such as 5G. Cooling energy need is also expected to increase in indoor telecom rooms, and can be as high as the equipment’s own power consumption. The world’s first liquid Base Transceiver Station (BTS) was adopted into commercial use in 2018, in Helsinki, Finland. Conventional air-cooled BTS hardware was converted into liquid-cooled BTS equipment. Heat from the BTS was pumped out of the site room, and thus ventilation or air conditioning was not needed for the heat load from the BTS. Heat stored in the liquid was released into the ventilation duct of the building, still providing annual cooling energy savings of 70%, when compared to air cooling. In the future, 80% of the total dissipated energy, 13450 kWh/a in total, can potentially be used for heating purposes. In terms of CO₂ emissions, adapting liquid cooling showed an 80% reduction potential when compared to air cooling.