On Sunday amidst the heat wave, New Yorkers set a record for Sunday electricity usage in the city. How does the city cope with peak energy demands?

According to Kate Ascher in The Works: Anatomy of a Citythe city has utilized a fleet of power barges located in the Gowanus Bay and at Sunset Park since 1975 to meet peak demand. The floating mini power plants run on natural gas. Although they typically serve as emergency power sources, some have become more permanent in New York City’s energy landscape over the past few decades. In the summer of 2001, six additional floating power plants were added  in response to warnings that the metropolitan area could meet power shortages. Most power barges do not have their own propulsion system and have to be towed, but “power ships” are being developed by repurposing former freighters

When the city has reached sweltering temperatures on the sweatiest summer days, the New York Independent System Operator (ISO) coordinates the flow of electricity accordingly by issuing a “max gen pickup alert.” This ultimately authorizes each of the power plants within the city’s grid and the generators along the Brooklyn Waterfront to run at maximum output. At the same time, the ISO will attempt to maximize the amount of energy flowing into Manhattan from upstate as well as New Jersey. Of course, if there’s still more demand than supply, energy conservation methods such as reducing light, elevator and air conditioning usage will be implemented.

It’s no surprise that New York City has become more wary about power outages since Hurricane Sandy (and the great summer blackout of 2003). A floating power plant was recently proposed that could provide immediate backup power to critical structures during an emergency. If it gets funded, the plant would be situated in the Wallabout Channel next to the Brooklyn Navy Yard.

Read more about New York City’s urban infrastructure in Kate Ascher’s book The Works: Anatomy of a City. Also check out our article about the New York City’s Temple of Power: the 59th Street Powerstation.