A $7 million upgrade to the Water Pollution Control Plant in the City of Schenectady will save the city an estimated $300,000 annually.
The completed sewage treatment plant was unveiled on Wednesday, May 2, for city officials and the media to tour. The project included a combined heat and power (CHP) system that produces biogas and uses an internal combustion engine to create electricity. The New York State Energy Research and Development Authority provided a $1 million towards the project.
“By generating electricity from biogas and capturing the extra heat to help with processing waste, the City of Schenectady is getting a two-for-one deal in clean energy,” Francis Murray Jr., president of NYSERDA, said in a statement. “Combining anaerobic digestion and CHP makes sense at any facility that processes a large amount of organic waste materials. The city should be commended for its effort to reduce its energy costs and greenhouse gas emissions.”
The Schenectady plant treats an average of 14 million gallons of wastewater per day. The plant serves about 85,000 area residents, including residents of Scotia, Alplaus, Glenville and portions of Niskayuna and Rotterdam.
Using new equipment, the plant is estimated to generate 1,800 megawatt-hours of electricity per year from the biogas, which is enough to power more than 275 private homes for a year. This will help offset energy costs of the plant and combined with other improvements it is estimated to save $300,000 in energy costs annually.
“The city is very pleased to see the wastewater treatment achieve greater energy efficiency while continuing its modernization efforts,” Schenectady Mayor Gary McCarthy said in a statement. “I want to thank NYSERDA for its generous support in helping the plant serve our local residents the best way it can.”
The CHP system uses anaerobic digestion, which is a process that breaks down biological materials, to produce the biogas. At the plant, sewage is treated and the thickened sludge is mixed and heated to allow the waste to break down and generate methane. The methane is purified and combusted to generate electricity.
Another energy-efficiency feature is the plant’s equipment recaptures the waste heat from burning fuel and reuses it to “enhance the digestion process” and provide heat to two buildings. The entire process also reduces odors and results in a finished product that can be used for compost, according to NYSERDA.
The facility dates back to the early 1900s and was still using equipment that was more than 50 years old before the rehabilitation project. Additional upgrades at the facility include new technology that reduces the water content of sludge before processing, new equipment to insulate and seal the anaerobic chamber and equipment to remove acidic hydrogen sulfide from the biogas to protect equipment from corrosion.
A U.S. Department of Energy grant of $600,000 also helped fund the project as well as a general energy-efficiency study for the city.
