Reliability and economic impacts of utilizing battery energy storage in data centers for energy flexibility services in smart grids

There are increasing interests in engaging data centers to provide energy flexibility services in power grids, due to their enormous energy consumption and storage capacities. However, two fundamental questions should be addressed urgently before wide applications, but not yet addressed sufficiently: what are the impacts of such engagement on the operational reliability and economics of data centers, and to what extent the energy storage can be utilized? This study, therefore, developed a systematic approach for assessing the reliability and economic impacts of utilizing battery energy storage in data centers. The impacts are assessed comprehensively for different tiers of data centers for providing typical grid services under different grid scenarios, considering the difference between reliability-based standards and system-based design standards for the first time, while making the reliability assessment of data centers more meaningful in engineering practice. Monte Carlo simulation is adopted to determine the stochastic battery backup time of data centers. Revenue models are developed to assess the economic benefits of engaging data centers for four typical energy flexibility services. A data center in Hong Kong is selected to perform the impact assessment. It is found that the data centers with the backup system designed using a system-based design standard can provide energy flexibility services effectively while satisfying the reliability-based standards. The economic benefit is found to be very significant, e.g. daily avenue up to USD$0.58 per kVA load, which is affected significantly by the services provided, power grid reliability and tier of data center.