February 15, 2008

Aggregated backup generators help support San Diego grid

Dr. Robert Peltier, PE

Performance under fire

On October 24, 2007, the EnerNOC program was put to the ultimate test. In response to electricity shortages caused by multiple wildfires in southern California, the California Independent System Operator declared a state of emergency. With the overall electricity supply in jeopardy, the NOC was notified and, within minutes, the Clean Gen program was supplying approximately 17 MW of electricity to the grid. This event wasn’t the first time the program had been called into action, but it was the first time in an emergency situation, and the results strongly validated the program.

“The Clean Gen program functioned just as it was designed to, helping us to meet our needs for increased electricity production through a system of aggregated back-up generators,” said Matt Burkhart, vice president of electric and gas procurement for SDG&E. “The rapid response of the EnerNOC team was especially impressive and helped us address the situation before the threat of brownouts became a serious concern.”

With field-proven effectiveness, even under emergency circumstances, programs like Clean Gen offer an innovative, economic approach to tackling peak demand crises. According to Healy, “A 100-MW aggregated backup generator program is cheaper to build, cheaper to maintain, has no transmission losses, and takes just a few months to build. On the other hand, a gas peaking power plant can be 60 times the capital cost, be more expensive to run, and take three years to build” (Table 2).

  Table 2. Demand response vs. peakers. Instituting a 100-MW demand response program is considerably more cost-effective than installing a 100-MW GE LMS 100 in a constrained air shed. Source: EnerNOC