Risk‐based stochastic day‐ahead operation for data centre virtual power plants

Abstract

Data centres (DCs) have rapidly expanded in recent years due to increasing demand for cloud services. The costs incurred by electricity and water consumption contribute to a major portion of DC operating costs. This article addresses the day-ahead operation of a DC in the context of a virtual power plant (VPP) under the grid-connected mode. The day-ahead operation problem is formulated as a two-stage stochastic mixed integer linear programming (MILP) model that considers workload schedules among server clusters, water consumption, and uncertainties of onsite renewable energy and electricity prices. In addition, the conditional value at risk (CVaR) is utilised to manage the risk caused by various uncertainties that challenge DCs, especially electricity prices. The impacts of the risk level, the water price, and uncertainty on the day-ahead operation of the DC are studied. The numerical test results show that the proposed model can efficiently generate optimal dayahead schedules.

Energy management for data centre microgrids considering co‐optimisation of workloads and waste heat

“…Without the loss of generality, batch workloads in this study are described by the following characteristics: required CPU frequency, execution time periods, continuous execution requirements (i.e. continuous or interruptible workload), and completion deadline [24,25].…”

“…Related constraints, such as DG units, BESS, and minimum on/off time constraint of server clusters can be found in our previous work [25]. In addition, CHP units are modelled using a standardised formulation [29].…”

Hybrid uncertainty‐based offering strategy for virtual power plants

“…To address specific challenges such as the intermittent nature of distributed renewable sources and their participation in the electricity market, the concept of a virtual power plant (VPP) has been developed [7]. Distributed energy resources (DERs) are indirectly enabled to contribute in the wholesale electricity markets via VPPs, since they can participate in these markets just as a conventional generation plant can [8][9][10]. Different applications of VPPs in a power system have been investigated in various studies [11][12][13][14].…”

Coordinated optimal dispatch of VPPs in unbalanced ADNs

“…Economic dispatch (ED) plays a fundamental role in the powers system and has been implemented in VPP operations [2,3,[6][7][8][9]. Table 1 concludes the characteristics of state of the art and makes a comparison with the proposed strategy.…”

“…Most previous commonly employed simple power flow equations in ED should be improved to accommodate aforementioned issues in ADN. Simplified power balance or DC power flow model is considered in [2,3,[6][7][8] neglecting power loss for DN and the P-Q coupling impact on voltage operation feasibility. A relaxed power balance considering high R/X ratio is presented in [9] but only DGs are considered excluding other DER.…”