Optimizing the power factor of data centers connected to the smart grid

The Data Centre (DC) services business is blooming increasing their energy demand and making them important players in the safe operation of the smart grid. The DC IT servers have a dynamic power factor varying from 0.98 for high density workloads and 0.8 for 20% server usage. A sub unitary power factor means that the voltage and current waveforms are not in phase making the electrical grid less efficient thus increasing the network loses. To make things even more challenging lately the grid operators have started to charge penalties if DC power factor is sub unitary. To improve their power factor with no extra hardware and no retrofitting, we propose an innovative method based on scheduling delay tolerant workload to achieve high servers' level usage thus increasing the leading factor and dynamically usage of nonelectrical cooling mechanisms such as the Thermal Energy Storage (TES) and this way increasing the lagging power factor. Simulation results are promising showing that a power factor with a value close to 1 can be achieved and maintained by proper planning the DC flexible power resources operation.