By Lucas Compan

New York’s photogenic vapors are at once mysterious and commonplace. You probably first saw this iconic steam on TV or in a movie. It’s especially prominent in Scorsese’s Taxi Driver. But whether you’re a visitor, a resident, or a long-distance admirer, this Manhattan spectacle is one of the many small sensory effects that make New York streetscapes so distinctive. The plumes are the perfect visual shorthand for Gotham’s underworld machinations—sandhogs and subways, schist and sewers. Browse these pictures and facts about the New York's steam system and watch the video by The New York Times at the end of this story.

Okay, but where does this steam come from? The Steam Monster smoking marijuana?

The answer is ConEdison, New York City’s venerable power company, pipes steam to customers in Manhattan just like any other utility product (such as gas, water, or electricity). The steam—some purposely created, some a ‘waste’ byproduct of electricity generation—comes from power plants.

What’s the steam used for?

A little bit of it is used as, well, steam—to operate laundries and even to sterilize hospital equipment. But a lot of it is used to heat buildings and their water supplies. Surprisingly, given that the steam’s temperature is around 350 degrees Fahrenheit (176 degrees Celsius), it’s also used to cool buildings, via the dark magic of absorption refrigerators. According to Michael Clendenin, director of media relations for Con Edison, the use of steam to cool buildings results in a big reduction in summer demand on the electricity grid.

Urban steam systems offer significant advantages because a large power plant is generally much more efficient than individual boilers in buildings. Measures to reduce air pollution can be centralized, too. 

But given the significant cost of infrastructure—a whole set of pipes under a city doesn’t come cheap—urban steam makes the most sense in densely populated areas. Manhattan, say.

The ConEdison steam distribution system

If the steam is so useful, why is so much of it wafting up into New York’s streets? Much of the steam drifting atmospherically toward the stars isn’t steam from the steam system—rather, it’s produced when water (at least, let’s hope it’s water) from other sources comes into contact with the steam system and is heated by steam itself. Safety valves may also release steam, as do leaks. Had it not being for the steam system, the postcard skyline that you see of Manhattan would be entirely different. You'd be looking at every single one of these skyscrapers with some type of chimney coming out of them.

Now watch this excellent video by The New York Times and learn even more

Keep exploring

Share the steam