California electric utilities have been exploring the use of dynamic critical peak prices (CPP) and other demand response programs to help reduce peaks in customer electric loads. CPP is a tariff design to promote demand response (DR). Levels of automation in DR can be defined as follows. Manual demand response involves a potentially labor-intensive approach such as manually turning off or changing comfort set points at each equipment switch or controller. Semi-automated demand response involves a pre-programmed demand response strategy initiated by a person via centralized control system. Fully automated demand response does not involve human intervention, but is initiated at a home, building, or facility through receipt of an external communications signal. The receipt of the external signal initiates pre-programmed demand response strategies. We refer to this as auto-DR.
This chapter describes the development, testing, and results from automated CPP (Auto-CPP) as part of a utility project in California. The chapter presents the project description and test methodology. This is followed by a discussion of auto-DR strategies used in the field test buildings. We present a sample auto-CPP load shape case study, and a selection of the auto-CPP response data from September 29, 2005. If all twelve sites reached their maximum saving simultaneously, a total of approximately 2 MW of DR is available from these twelve sites that represent about two million ft2. The average DR was about half that value, at about 1 MW. These savings translate to about 0.5 to 1.0 W/ft2 of demand reduction. We are continuing field demonstrations and economic evaluations to pursue increasing penetrations of automated DR that has demonstrated ability to provide a valuable DR resource for California.