The more successful a utility’s demand response program is, the more difficult it is to find additional targets for it.

“About 5% of our load is on an interruptible or curtailment rate, so it is getting more difficult to find more,” explains Jim Eber, tariff products manager for Commonwealth Edison (ComEd), a subsidiary of Exelon Corp.

Chicago-based ComEd has a peak demand of about 22,000 MW during the hottest days of the summer and about 1,200 MW locked up on its demand response programs, says Eber. Demand growth is between 1.5% and 2% annually.

To expand its demand response program—“We are always looking for ways to increase the efficient use of load management,” Eber says—ComEd decided to outsource a lighting program to Electric City, a developer, manufacturer, and integrator of energy savings technologies and building automation systems based in Elk Grove Village, Ill.

Virtual negawatts

For ComEd, Electric City is developing a $25 million, 50-MW power curtailment system and will get paid by the utility based on performance. Details of the financial arrangement and the performance criteria are confidential, says Eber. The program—which Electric City has dubbed the Virtual Negawatt Power Plan (VNPP)—will allow ComEd to remotely control commercial, industrial, and government lighting systems over a managed and secure IP network. Lighting currently represents about 30% of ComEd’s total load, making it ripe for conservation.

When needed, ComEd will ask Electric City to activate its equipment installed on end-user lighting systems, a process that gradually dims lighting over several minutes. Depending on customer preferences, the lights are dimmed 15% to 30%. “If you are in the room while it is happening, you don’t really notice it. Only if you leave before it starts and return after dimming will you notice that something is different,” says Eber.

Electric City will guarantee the delivery of peak power reduction through what it calls its EnergySaver/GlobalCommander system and will dispatch load at the direction of ComEd. In exchange for hosting the system and allowing remote control over peak demand, customers will receive the technology for free and will receive free steady-state energy savings.

Electric City said its system is programmable to provide the precise amount of power each lighting load needs to fully function properly. The fluctuations in power supply are eliminated, the power is conditioned, and the quality of the electricity is enhanced. Electric City’s self-contained system can interface with existing lighting panels and lamps/ballasts without rewiring and has no moving parts. ComEd and Electric City expect about 1,500 EnergySaver systems will be installed under the project.

Several large entities have already signed on. In October, Chicago’s Metropolitan Pier and Exposition Authority (MPEA) signed a preliminary agreement to participate. The deal covers all facilities owned and operated by the MPEA, including large portions of McCormick Place, Navy Pier, and parking facilities. About 100 EnergySaver systems will ultimately be included in the MPEA project.

Recently, the Illinois Department of Central Management Services (DCMS) also agreed to participate. This agreement includes all DCMS facilities in ComEd’s service territory, approximately 30 buildings. The DCMS deal represents about half of the program’s 50 MW target, Electric City says. The city of Rosemont, Ill., also agreed to participate in the VNPP offering. The Rosemont agreement includes a number of city facilities and the Rosemont Convention Center. Being evaluated is applicability of the Allstate Arena, also owned by the city. Other participants are the city of Chicago Ridge and the Chicago Ridge Shopping Mall, also owned by the city.