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ENERGY SAVERS
Bergen County Utilities
Authority
Combined Heat and Power
Cogeneration Unit
The Bergen County Utilities
Authority (BCUA) has been in the forefront of sustainable
energy for their facilities for economic, environmental
and energy saving reasons. A Sustainable Energy Master
Plan has been developed addressing all of BCUA’s
sustainable programs as well as planning for the future.
An early example of the BCUA’s sustainable energy programs
is the combustion of biogas generated in their anaerobic
digesters at their Little Ferry Water Pollution Control
Facility (WPCF) in the boilers and aeration tank blower
engines which reduced the purchase of external sources of
energy.
In June 2008, the BCUA took
this to the next level by commencing operation of a
combined heat and power (CHP) cogeneration unit (CoGen)
located at the BCUA water pollution control facility in
Little Ferry. The cogeneration unit has the capability of
burning natural and digester gas. Using the CoGen system
to generate 21,869,154 kilowatt-hours of electricity would
produce approximately 56 percent of the total electrical
consumption for the BCUA. Along with the additional 28
percent electrical avoidance induced by the blower engines
the BCUA can produce on-site 85 percent of its energetic
requirements. The waste heat recovered from the CoGen can
supply 47 percent of the plant process heat requirements.
In addition, the recovery of the CoGen waste heat reduces
the combustion of fossil fuel oil in the plant boilers
which results in the reduction of greenhouse gases.
Since the startup of the
CoGen system, the BCUA saved over $800,000 during the last
seven month period by avoiding the purchase of natural gas
and electricity from the grid.
The CoGen unit is a
hallmark of a Sustainable Energy Master Plan that the BCUA
has developed to (i) examine and analyze past efforts in
energy savings, and (ii) plan for future efforts in energy
savings and greenhouse gas reduction. Future plans are
already being developed for green roof technologies, solar
power, additional microturbines to burn biogas, and a
pilot study to inject waste brown grease into the
anaerobic digesters in order to increase biogas production
for the CoGen unit and other combustion units. |
Energy Savers
Passaic Valley Sewerage
Commissioners
Oxygenation Tanks
In 2008 Passaic Valley
Sewerage Commissioners completed the conversion of its
Oxygenation Tanks activated sludge treatment process.
Originally, oxygen was added to the process using 16 air
compressors that pushed air into 48 mixertype rotatin
spargers that submerged 30 feet into the tanks. The new
system uses 48 surface aerators which eliminate the need
for 16 air compressors. This reduced the system’s full
load by 2,800 horsepower and dropped PVSC’s electrical
demand by nearly 2,000 Kilowatts. The new system will save
PVSC approximately $1,700,000 annually on its electric
bills.
Also, under an existing
incentive program, PSE&G has agreed to pay PVSC
approximately $800,000 annually for the energy saved by
this project through 2015. The total cost benefit to PVSC
for implementing this project is $2,500,000 annually.
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