Serving the Grid: an Experimental Study of Server Clusters as Real-Time Demand Response Resources

Demand response is a crucial technology to allow large-scale penetration of intermittent renewable energy sources in the electric grid. This paper is based on the thesis that datacenters represent especially attractive candidates for providing flexible, real-time demand response services to the grid; they are capable of finely-controllable power consumption, fast power ramp-rates, and large dynamic range. This paper makes two main contributions: (a) it provides detailed experimental evidence justifying this thesis, and (b) it presents a comparative investigation of three candidate software interfaces for power control within the servers. All of these results are based on a series of experiments involving real-time power measurements on a lab-scale server cluster. This cluster was specially instrumented for accurate and fast power measurements on a time-scale of 100 ms or less. Our results provide preliminary evidence for the feasibility of large scale demand response using datacenters, and motivates future work on exploiting this capability.