Eight aeroderivates on barges to power New York City

New York City may soon be powered with two new power barges with eight Siemens 76-MW aeroderivative gas turbines.

Under a announced contract signed by Astoria Generating Co. (AGC) and Siemens, the power barges will replace two of four existing power barges at the 640-MW Gowanus Generating Station in the Upper Bay of Brooklyn and two other power barges at the nearby 320-MW Narrows Generating Station.

The existing Gowanus plant is a fuel oil and natural gas facility that has 32 simple-cycle combustion turbine units (16 can be dual-fired) situated equally across four floating barges that are moored to a pier located on Gowanus Bay in Brooklyn. One of the largest floating power plants in the world, Gowanus spans across 25 acres of piers and submerged land. The units are flexible and can start up with 15 minutes notice and are available year-round to offer system peaking capacity. The 1971-built plant is connected to an existing natural gas pipeline, a 138-kV transmission line to a ConEd substation close by, and water supply and wastewater pipelines. The 1972-built Narrows, also located in Brooklyn, features 16 simple cycle combustion turbine units, all with dual-fuel capability.

AGC, an Eastern Generation subsidiary, acquired both plants (along with the 959-MW Astoria Generating Station in Queens) from Consolidated Edison Co. of New York in 1999, as New York’s power market underwent restructuring. AGC last year proposed repowering the 1971-built Gowanus four-barge station and retiring the Narrows station because the aging plants faced new rules from the Department of Environmental Conservation (DEC) that would require add-on pollution controls systems for reducing nitrogen oxide emissions from older peaking units.

The current Gowanus facility, which is positioned to operate through “extraordinarily high tide and storm surges and to adapt to future water level rise,”  continued to operate through Hurricane Sandy with “minimal impact,” AGC noted. The plant, now approaching 50 years of age, was also one of the first generating stations to resume operations following the August 2003 blackout, ACG noted. Retirement of Narrows, it noted, also opens up the possibility of using interconnection infrastructure at the facility to support offshore wind resources or “provide opportunities for energy storage (potentially on barges),” opportunities the company said it is exploring.

Siemens is marketing SeaFloat power plants as an alternative to stationary projects that can be used as baseload or emergency backup during peak loads or outages. Barges can also be supplemented with a desalination plant to provide potable water. “Mobility, flexibility and no need for land acquisition are the most prominent features which distinguish SeaFloat power plants from conventional land-based plants. These features come along with short lead time due to high prefabrication grade and enhanced plug and play concept as well as reduced overall project investments making them interesting for various applications,” the company said.