Demand Response in Data Centers

Demand Response in Data Centers

An earlier study (see  Documents  tab) performed in collaboration with technology experts, industrial partners, and data center facility managers found that data centers, with significant and rapidly growing energy use, have significant potential to shift or shed electric load for short periods of time when the electric grid is stressed (typically due to extreme weather or unexpected shutdown of key resources).  Such a short term shift or shed of electrical load is referred to as "Demand Response" (DR), because it is an on-demand response to signals from electricity suppliers.  Formally, 

•       DR is a set of actions taken to change electric loads, when

–      system-wide grid contingencies occur that threaten the supply and demand balance or

–      market conditions occur that change electricity costs

•       It is distinct from energy efficiency (permanent reduction of energy use while maintaining comfort) – DR is a short term alteration of energy use (relatively few days/year), usually with an incentive or reward

Strategies for data centers to shift or shed short term energy needs include:

1. virtualization, by which loads are consolidated as needed, can reduce IT equipment energy use, which correspondingly reduces facility cooling loads
2. colocation, or moving loads to an offsite location where time of use electric pricing is lower
   
3. changes directly impacting data center support infrastructure such as lighting, and heating, ventilation, and air conditioning (curtailment or precooling)
   

Because data centers are highly automated, they also expected to be excellent candidates for automating DR.