Data centres in the ancillary services market

Ancillary services are the mechanisms power grids use to address short-term variability in supply and demand as well as the impact of power plant or transmission line failures. Organizations providing such services can earn revenue, or at least reduce their energy costs. This paper explores options for large data centres to reduce costs in this way. Simulation results are presented for a system that models the processing of a workload and the resulting energy use, focusing on the impact of providing specific types of ancillary services. Trace data recording the workload from three supercomputing facilities along with pricing information from a US-based electrical grid are used. Results presented show energy costs reduced by up to 12% with only a small impact on the quality of service provided to users of the data centre. Further reductions in energy costs are shown for data centres willing to cede more control over short-term energy consumption.