Location: Yonkers, New York
Host: Westchester County Department of Environmental Facilities
Rating: 200 kW (ac)
Installation Date: April 1997
No. of Units: 1
Technology: Phosphoric Acid
Fuel: Anaerobic Digester Gas
Silent, with no moving parts and virtually exhaust free, a Power Authority-installed fuel cell supplementing the power supply at the Westchester County Wastewater Treatment Plant in Yonkers, New York, has one additional and remarkable distinction: It’s the first in the world to run on anaerobic digester gas (ADG). Fuel cells normally run on natural gas.
A byproduct of sewage treatment, ADG, if released into the atmosphere, contributes to the “greenhouse effect,” which some scientists believe to be a cause of global warming. Flaring, or burning off, the gas, although mitigating the problem in recent years, also contributes to polluting the air. NYPA installed the 200-kilowatt Yonkers unit in 1997 to assess its environmental and economic benefits through ongoing testing.
The Yonkers fuel cell avoids flaring of most of the ADG, instead using it as “free” fuel to create electricity. Inside the unit, hydrogen from the ADG reacts with oxygen from the air to create electricity. Fuel cells are exceptionally clean and efficient. Air emissions are much lower than from a typical fossil-fueled power plant. A typical fuel cell powered by Anaerobic Digester gas generates about 1.6 million kilowatt-hours of electricity a year while releasing only 72 pounds of emissions into the environment. The average coal- or oil-fired plant generating the same amount of electricity produces more than 41,000 pounds of pollutants, including almost 30,000 pounds of sulfur oxides and 11,000 pounds of nitrous oxides.
The Yonkers installation has earned a number of awards and international recognition.