Leveraging distributed UPS energy for managing solar energy powered data centers

As the essential infrastructures for cloud computing, data centers are facing increasing pressure of capping tremendous power consumption and carbon emission. Currently, many proposals have leveraged energy storage devices (in the form of UPS batteries) to provide buffered energy during peak power demands for reducing data center power cost. In addition, energy storage devices are also used to smooth out power supply variation in renewable energy powered data centers for effectively cutting down carbon emissions. However, a joint management of peak power shaving and renewable energy harvesting in data centers is still lacking. Existing schemes either incur green energy efficiency degradation or sacrifice data center availability and workload performance. In this paper, we propose a novel power delivery scheme Re-UPS, which is based on existing UPS infrastructures and employs renewable energy to cap peak power consumption and carbon emission in data centers. Re-UPS leverages distributed energy storage architecture and dynamic online heuristic energy management strategy to enable data centers to achieve the best optimization among maximizing renewable energy harvest, shaving peak power demands and improving UPS system availability. We evaluate Re-UPS under different environmental conditions and workload. Our results show that Re-UPS can increase green energy utilization by 74.1%, improve backup energy capacity by 16.5%, and extend the battery life by 10.6%.