This book constitutes the thoroughly refereed post-conference proceedings of the First International Workshop on Energy Efficient Data Centers (E2DC 2012) held in Madrid, Spain, in May 2012. The 13 revised full papers presented were carefully selected from 32 submissions. The papers cover topics from information and communication technologies of green data centers to business models and GreenSLA solutions. The first section presents contributions in form of position and short papers, related to various European projects. The other two sections comprise papers with more in-depth technical details. The topics covered include energy-efficient data center management and service delivery as well as energy monitoring and optimization techniques for data centers.

European Green Data Center Initiatives.- Setting Energy Efficiency Goals in Data Centers: The GAMES Approach.-Sustainable Energy Management in Data Centers through Collaboration.-Modeling and Simulation of Data Center Energy-Efficiency in CoolEmAll.- SLAs for Energy-Efficient Data Centers: The Standards-Based Approach of the OPTIMIS Project.- The GreenIT DC-Benchmarking Tool: From Scientific Theory to Real.- Energy-Efficient Data Center Management and Service Delivery.- GreenSLAs: Supporting Energy-Efficiency through Contracts.- Exploiting VM Migration for the Automated Power and Performance Management of Green Cloud Computing Systems.- Energy Efficient Service Delivery in Clouds in Compliance with the Kyoto Protocol.- Data Center Energy Monitoring and Optimization.- Implementation and Evaluation of a Wired Data Center Sensor.- Energy Usage and Carbon Emission Optimization Mechanism for Federated Data Centers.- DNA-Inspired Scheme for Building the Energy Profile of HPC Systems.