The environmental policy of KPN has an objective of reducing CO2 emissions and energy consumption to contribute in making the planet more sustainable. This thesis project researches the potential for reducing energy consumption and, consequently, the operational costs of the KPN LTE network. There are various resources in a mobile network which consume energy and switching off these resources will lead to a reduced energy consumption. The trade-off in switching off these resources involves a potential impact on the capacity and the quality (throughput) offered by the mobile network. In this thesis we quantify the attainable savings in operational cost and/or energy consumption while still satisfying the quality of service requirements set by KPN. Five different operational cost saving schemes are analyzed on three different timescales in this research. The results of this research indicate that there is ample opportunity present for KPN to reduce their operational cost and/or energy consumption with minimal impact on the quality of service. The results further indicate that maximum savings are attainable in the live KPN network by effectuating the ’turning off carriers’ scheme, in which the capacity carrier is turned off at the base stations. The reduction in energy consumption and operational cost on effectuating this energy reduction scheme is in the range of 21-70% with respect to the reference scenario for each of the timescale. Furthermore, the results also indicate that of the five operational cost saving schemes investigated, the ‘turning off carriers’ scheme has the lowest impact on the experienced quality of service.