Federated data centers as smart city stabilizing factors

The increasing demand for highly sophisticated cloud services and the consequent worldwide increase in the number of data centers (DC), make the need for energy efficient operation of DCs more actual than ever. Additionally, in the context of smart city and smart grid integration, flexible DCs can play a key role toward acting as grid-stabilization factors. In this paper, a review of the available techniques toward energy-efficient DC operation is performed. The available techniques give rise to four axes of flexibility within a federated DC network. Next, the applicability of the flexible, energy-efficient DC operation is highlighted, by proposing a simple scheduling algorithm, applicable to legacy DC equipment, for effective host and re-arrangement of the DC computing load. The proposed algorithm can provide substantial energy savings during periods of low computing load and improved Quality of Service during periods of high computing load. Concluding, the paper focuses on the grid-stabilization aspects of a federated DC network and the interoperability with the energy network via an Electronic Energy Marketplace in the context of a Smart City.