Con Edison's steam system supplies heat, hot water, and cooling to customers in Manhattan, including many of New York's most famous landmarks. The company's central steam generating stations have enabled many of New York City's skyscrapers, apartment complexes, and cultural institutions to be built without individual boiler plants, and therefore without chimneys or smokestacks on every building. This eliminates local dispersion of air pollutants at lower elevations.
Con Edison's steam plants reduced emissions and lowered costs to steam customers in 2011 thanks to two efforts. First, the steam production boilers at the Hudson Avenue Generating Station were retired, and second, the steam system was operated for a full year according to modified, more-efficient operating criteria.
Hudson Avenue was the largest steam-power plant in the world at the time of its completion in the early 1930s. Of the original 32 boilers, 28 were retired in previous years, and by 2011 only four boilers remained in service with a total capacity of 1,600,000 pounds of steam per hour. By retiring these four oil burning steam boilers in February 2011, the associated air emissions were displaced by gas fired cogeneration units at Con Edison's East River plant, or a non-affiliated Brooklyn Navy Yard plant. Both of these plants utilize cleaner fuels, and have better emission controls than the now-shuttered Hudson Avenue plant.
The following video is a segment from Con Edison's The Excellence Files, which is a monthly internal video newsmagazine program that highlights the company's work on environment, health, and safety issues.
The steam system's operating criteria was modified in December 2010 to lower the average system operating pressure during the winter, and to reduce the amount of idling reserve generation requirements. These modifications came after a detailed assessment of customer pressure requirements. This modification, which was in full practice for all of 2011, allowed the company to run its most efficient steam production units more frequently, and reduce the usage of the least efficient units.
The company is also moving forward with gas addition projects at its 59th Street and 74th Street Generating Stations. Currently there is limited gas-burning capability at the 59th Street Generating Station, and no gas-burning capability at the 74th Street Generating Station. These projects are expected to be operational by January 2014 to comply with new emissions regulations going into effect in July 2014. While the addition of clean-burning gas at these facilities is an important aspect to our air-emissions compliance strategy, the company is also anticipating significant savings for its steam customers in the near-term due to the lower price of natural gas, which will displace the #6 fuel oil currently burned at the 59th Street and 74th Street Generating Stations. The total annual emissions reductions for both Generating Stations due to the gas addition projects is estimated to be approximately 74,000 tons of CO2, 490 tons of NOx, 930 tons of SO2, and 135 tons of particulate matter. The estimated 74,000 ton reduction in CO2 equates to about a 10 percent and 13 percent reduction for 74th Street and 59th Street Generating Stations, respectively.