Real-time Operation of a Data Center as Virtual Power Plant Considering Battery Lifetime

Data centers have significant capital investments in large underutilized energy resources in the form of backup generators and batteries. In this paper, we propose to use these energy resources in demand response (DR) by operating a data center as a virtual power plant (VPP). An optimization model is designed which schedules the energy resources on a day-ahead basis using forecasted values of both renewable energy sources and the data center load for participation of the data center in DR. This optimization model also incorporates realtime dispatch of units to handle variations during operation. An improved battery cost model is designed and implemented as a soft constraint in the VPP energy management system (EMS) model, ensuring that the batteries' use in DR does not affect their float life. A case study is conducted in which the data center is connected to bus 8 of the modified IEEE 30-bus system. The results show that real-time operation of a data center participating in DR significantly reduces the operational cost, especially during network congestion, without causing battery degradation.