Information is at the core of any business, but storing and making available all the information required to run today's businesses have become real challenges. While large enterprises currently face difficulties in providing sufficient power and cooling capacity for their data centers, midsize companies are challenged with finding enough floor space for their storage systems. Data storage being responsible for a large part of the energy consumed by data centers, it is essential to make storage systems more energy efficient and to choose solutions appropriately when deploying infrastructure. This chapter presents the state of the art on technologies and best practices to improve the energy efficiency of data storage infrastructure of enterprises and data centers. It describes techniques available for individual storage components--such as hard disks and tapes--and for composite storage solutions--such as those based on disk arrays and storage area networks.