Santa Clara County Case Study


Applied Power Technologies, Inc. is a certified Technical Coordinator (TC) for PG&E’s Automated Demand Response Program (ADR). APT was con- tracted by the County of Santa Clara as their TC to integrate nine county campuses to automatically reduce demand when required. The County received an immediate cost savings from a lower Time of Use electric rate.

PG&E’s Automated Demand Response program funds Lawrence Berkeley National Labs’ energy audits analyzing building mechanical and lighting systems to find the best areas for load shedding. This analysis also estimates the kW demand reduction, reserving a financial incentive for the customer.


Background on Automatic Demand Response

The basic principle behind demand response is that it can be a dynamic means of energy load reduction. When the demand for power peaks (usually caused by high temperatures driving HVAC load) the California Independent System Operator (Cal ISO) energy generation and transmission system’s capacity is fully utilized. The utility will notify Demand Response customers to reduce load, eliminating the need to start resource intensive additional power plants. Participation in the Automated Demand Response program means the load shed strategies are preconfigured into the customer’s computerized control system, and these load sheds are triggered via a signal from the utility.



The demand response season for PG&E customers runs during theirsummer peak season (May 1st to October 31st). In 2009 there were a total of 22 events initiated by the California ISO. Twelve of the eventsspecifically called on Critical Peak Pricing customers, including theCounty of Santa Clara, to participate. The technical incentives in 2009 were up to $300/kW to install equipment that will automatically shedload during events. During peak hours, if an event is called and the customer chooses not to shed load, the cost of energy during those hours can be up to five times the tariff amount.


The value of incentives can add up quickly. For example, one megawatt of demand response can provide up to $300,000 of incentive fundingto install new equipment.

The County has an extensive Energy Management System to isolateindividual sites for load verification. During the measurement and verification phase, each building was tested for appropriate response. After the ADR system was brought online successfully, the EMSreports in real time the performance and savings for each DemandResponse event. An example load reduction trend below is provided from the EMS.


Using ADR, the County has saved thousands of dollars and tens of thousands of kWH of energy. They also report to the public their reduced carbon emissions, and conserve resources for future generations of County residents.

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