On a hot afternoon, a New York office tower can dim its lights, chill its water tanks, and wait.
That pause is demand response: the building agrees to use less electricity when the grid is strained.
Instead of every air conditioner blasting at 4 p.m., Con Edison calls on large buildings to shed load for about 4 hours.
The trick is simple. The building gets paid for being flexible, and the grid gets breathing room when power plants are busiest.