As experimenting with energy-aware techniques on large-scale production infrastructure is prohibitive , a large number of proposed traffic-engineering strategies have been evaluated only using discrete-event simulations. The present work discusses (i) challenges towards building testbeds that allow researchers and practitioners to validate and evaluate the performance and quality of energy-aware traffic-engineering strategies , (ii) requirements to fulfill when porting simulations to testbeds, and (iii) two proof-of-concept testbeds. One testbed uses and provides Software-Defined Network (SDN) services created on the Open Network Operating System (ONOS) while the other is a composition of virtual Open vSwitches (OVS) controlled by the Ryu SDN framework. The aim of the testbeds is to validate previously proposed energy-aware traffic engineering strategies in different environments. We detail the platforms and illustrate how they have been used for performance evaluation. Additionally, the paper compares results obtained in the testbeds with evaluations performed using discrete-event simulations and presents challenges faced while implementing energy-aware traffic engineering mechanisms as SDN services in testbed environments.