The present document analyses the energy efficiency issues for the future 5G systems@ object of standardization in 3GPP and ITU and foreseen to be available from 2018 in various countries. The focus is about methods and metrics to measure energy efficiency in 5G systems@ considering the degree of stability of the systems known so far and the experience of the legacy systems and the related measurement procedures. In this approach@ the present document will rely on the existing standards for legacy radio systems@ especially ETSI ES 202 706 [i.1] and [i.2] for single base station measurements in a laboratory environment and ETSI ES 203 228 [i.3] for access network aggregate measurements of energy efficiency. These standards are currently studying 2G@ 3G and 4G energy efficiency topics. Moreover@ the present document considers also the state of the art in 5G energy efficiency studies to elaborate a first view on 5G@ to be further agreed for the possible future development towards a new standard of Energy Efficiency evaluation for 5G future systems.