Int. J. Critical Infrastructures, Vol. 3, Nos. 1/2, 2007 221 Copyright © 2007 Inderscience Enterprises Ltd. The effects of dynamic residential load participation: penetration levels for operational impact on reliability Steven R. Harper and Deborah L. Thurston* Department of Industrial and Enterprise Systems Engineering University of Illinois Urbana/Champaign 104 S. Mathews Avenue, Urbana, IL 61801, USA E-mail: srharper@uiuc.edu E-mail: thurston@uiuc.edu *Corresponding author Philip T. Krein Department of Electrical and Computer Engineering University of Illinois Urbana/Champaign 1406 West Green Street Urbana, IL 61801, USA E-mail: krein@uiuc.edu Abstract: Building an electrical load system that uses prioritised loads has been suggested as a means of approaching the overloading of the aging electrical infrastructure and thus increasing system reliability. In this paradigm, local controls would shut off electrical loads when overload conditions are being approached in the electrical power system. An unresolved question is how these systems might be configured and whether the deployment of residential load control will make a difference. This paper provides answers to both of these questions by suggesting several methods of deploying residential load control and determining the level of participation needed for each to make a difference in overall system reliability. The approach suggested was shown to improve the reliability of electrical power delivery, even under very modest levels of participation. Under emergency conditions with 10% of load available for control, there is a factor of ten improvement in electrical power system reliability. Keywords: load shedding; electrical power systems; system reliability; systems engineering; load management; reliability management; reliability estimation; residential load control. Reference to this paper should be made as follows: Harper, S.R., Thurston, D.L. and Krein, P.T. (2007) ‘The effects of dynamic residential load participation: penetration levels for operational impact on reliability’, Int. J. Critical Infrastructures, Vol. 3, Nos. 1/2, pp.221–234. Biographical notes: Steven R. Harper earned a BS in Engineering Physics from the University of California, Berkeley, 1981, and then served in the US Navy onboard submarines and as a Material Professional. He earned an ME in Electrical Engineering from the University of Virginia, 1988, an MA in National Security and Strategic Studies from the Naval War College, 1994. Upon retiring in 2002 as a Commander, he began study at the University of Illinois earning the MS in Business Administration, 2003, and a PhD in Systems and Entrepreneurial Engineering, 2006. He was a graduate research