The present document defines the metrics and measurement methods for the energy efficiency of functional components of NFV environment. The NFV functional components include Virtualised Network Functions (VNFs) and NFV Infrastructure (NFVI) defined in NFV architecture framework as described in ETSI GS NFV 002. Management and Orchestration (MANO) is not included as system under test@ but will be eventually taken as test environment. The measurement method described in the present document is intended to be used to assess and compare the energy efficiency of same functional components independently in lab testing and pre-deployment testing. Energy efficiency of co-located VNFs sharing same platform resources cannot be compared using the defined method in present document. The scope of the document is not to define measurement method in operational NFV environment. The present document is intended to define common energy efficiency measurement methods for NFV environments@ not try to cover all different types of VNFs (e.g. firewall@ gateway@ etc.)@ but it provides the basis to make extensible definition.