When energy demand is high and supply is short, San Francisco, California-based Pacific Gas & Electric (PG&E) offers financial incentives to companies that reduce their load in response to a request.
NetApp, a Sunnyvale, California company that creates storage and data management solutions, signed up for PG&E’s Demand Bidding Program, which means the utility pays NetApp $0.50/kWh when the request is made the day before and $0.60/kWh if the request is made the same day.
It started several years ago when NetApp saw an opportunity to significantly reduce energy consumption at its headquarters, which has 1.2 million square feet of space in 10 buildings. The headquarters uses 54 million kilowatt hours annually, with a peak demand of 7.6 megawatts. In 2008, NetApp’s annual utility bill was US$7.7 million, 89% of that for electricity.
Energy-efficient equipment is only part of the solution. “You also need to make intelligent decisions about equipment settings, and that requires gathering and analyzing information from disparate building systems, including metering systems and PDUs [power distribution units],” says David Shroyer, a NetApp controls engineer.
To aid that effort the company deployed the Network Building Mediator from Council member Cisco, which aggregates information from all of NetApp’s building systems, including lighting, heating, ventilation, air conditioning, temperature sensors and PDUs, from multiple vendors. Building engineers and facilities personnel can control systems in any building using a web-based interface. Demand response payments from PG&E paid for the system and NetApp has since deployed Network Building Mediator for automated demand response at its properties in Europe and India.
“Within 20 minutes of the demand-response signal from the utility, the Cisco Network Building Mediator reduces lighting by 50% and raises the temperature set point by four degrees, shedding 1.1 megawatts.”