The “Big Apple,” New York City, where does one start when describing this place! Home of so many landmarks , Statute of Liberty, Brooklyn Bridge, Manhattan, to name but a few!, the United Nations, Wall Street, we could go on. An unlikely place you might think to have a very big connection with steam.
New York is located on one of the world’s biggest natural harbours. Named New York in the 1660’s it has become a symbol of the United States, and home to over 8 million people in the city itself. Approximately 50 million people visit every year, and it’s a highly recommended place to visit too.
In addition to all of this New York City is in fact home to the biggest district steam system in the world. The New York steam company started providing steam to the city in the 1880’s and within the first year had 62 customers. Today the steam system it is operated by the Consolidated Edison Company of New York, Inc. It is transported by over 100 miles of steam mains and branches. This means that a building can connect and use steam in the same way most would have electricity or phone connections as it is viewed as a standard utility. Indeed the United Nations complex and the Empire state building are heated and cooled using steam (among over a thousand other buildings). Steam is generated in eight power plants to provide redundancy and spare capacity.
Steam can be provided to users from the southern tip of Manhattan to the area bordering Central park. The installed capacity from the eight power plants is approximately 6 million kg of steam per hour. The power plants are mostly dual fuelled so can run on low sulphur oil or gas giving flexibility. Five of the plants are located in Manhattan, one in Brooklyn, and one in Queens. Over forty percent of the steam generated is from CHP (combined heat and power), which is sometimes called cogeneration. Steam is the by-product of electricity generation. Normally involving a gas turbine and a heat recovery steam generator. The gas turbine turns the generator and produces electricity while the heat from the gas turbine exhaust is used to heat water and generate steam.
A district steam system like is the case in New York has a number of advantages. One of these being that the each building does not need its own boilers (for steam or indeed hot water generation) and associated equipment (exhaust stacks etc.). In a city where space is at a premium this is a real bonus. Steam is provided to the customer normally via a connection from under the street, with heating and hot water being achieved in the building by using simple steam to water heat exchangers. Chilling is achieved in the building by using steam chillers or electrical chillers. In practice there is usually a combination of steam and electric chillers.
If you are lucky enough to visit the city or when you see news reports from the United Nations, spare a through for the key roles that steam plays for New York!