[reblogged from underpaidgenius]
Patrick McGeehan, At Con Ed Nerve Center, Keeping the Lights On
Con Ed was using all available tools for suppressing demand for power throughout its service area. For a second day, it had put all of its emergency programs into effect, which combined to cut usage by about 400 megawatts, according to Mr. Miksad. With them, consumption peaked just below 13,000 megawatts on Tuesday and Wednesday afternoons. Without them, it would easily have surpassed the all-time high of 13,141 megawatts, he said.
One lesser-known contributor to the savings was a program that allows Con Ed to reprogram the thermostats in about 20,000 homes and businesses. Those customers are equipped with central air-conditioning systems controlled by thermostats with small antennas.
In times of unusually high demand for electricity, Con Ed tells Carrier, the maker of heating and cooling systems, to send a radio signal that causes those thermostats to cycle on and off every 30 minutes. Doing so shaved about 25 megawatts off the peak demand this week, Con Ed officials said.
“A megawatt here, a megawatt there can make a difference on a day like today,” Mr. Miksad said.
Appears like these units just are receivers. Would be better to make cooling systems addressable via Internet for two way signaling.