O
The American Recovery and Reinvestment Act (ARRA), Green Project Reserve of 2009, through the Clean Water State
Revolving Fund, provided funding for a wide variety of qualifying projects in the categories of: green infrastructure, energy
efficiency, water efficiency, and other innovative projects. For more information on projects that have been funded by the
Green Project Reserve and for additional details, visit www.epa.gov/ow/eparecovery.
Achieving Zero-Net Energy
at Drinking Water and
Wastewater Facilities
Adopting zero-net energy
principles to realize both
cost savings and increased
energy efficiency.
BACKGROUND Providing safe drinking water and reliable wastewater treatment is extremely
energy-intensive. An estimated 3% of total national energy consumption is
used for drinking water and wastewater services.
If the water and
wastewater sector
could reduce energy
use by just 10%,
collectively it would
save about$400
million annually.
By applying zero-net energy (or ZNE) principles,
water and wastewater utilities can reduce their
energy consumption, achieve greater energy
independence, realize significant cost savings,
and add to their bottom lines.
A zero-net energy facility is one that has
greatly decreased its dependence on outside
energy supplies moving toward a goal of
total energy independence. Facilities striving
to reach ZNE should first reduce the plant's
total energy needs through investment in
renewable technologies, reduced energy
consumption equipment, and operational
efficiencies using a variety of approaches,
including those described in EPA's Energy
Management Guidebook for Wastewater and
Water Utilities, available at www.epa.gov/
waterinfrastructure/pdfs/guidebook_si_
energymanagement.pdf. Achieving ZNE is
also an important element of effective utility
management consistent with the Attributes of
Effectively Managed Utilities supported by EPA
and major water sector associations.
Once the total operational energy needs
have been mitigated, alternative or "green"
power sources can be used for on-site energy
production. Through the use of low-cost, locally
available, nonpolluting, renewable energy
sourcessuch as solar cells, methane-powered
microturbines, and wind turbinesa utility can
generate enough renewable energy on site to
equal or even exceed its annual energy use.
-------
Case Study
www.epa.gov/ow/eparecovery
ADVANCEMENT
THROUGH
STIMULUS
FUNDING
Read about what three facilities in Massachusetts
have done to reach zero- or close to zero-net
energy through a combination of state and
2009 American Reinvestment and Recovery
Act (ARRA) funding. These facilities also
participated in a pilot program managed by the
Massachusetts Department of Environmental
Protection to help utilities across the
Commonwealth identify ways to improve their
overall energy efficiency. For more information
on this pilot program and its future expansion
to all 370 Massachusetts water and wastewater
treatment plants, visitwww.mass.gov/dep/
wate r/wa ste wate r/e m p i I ot. ht m.
TOWN OF FALMOUTH, MA: WASTEWATER TREATMENT FACILITY
Photo courtesy of Rose Forbes,
United States Air Force
The Town of Falmouth operates an advanced
nutrient-removal system that processes
approximately 0.4 million gallons of wastewater
per day. The facility treats wastewater and
domestic septage for the community.
Zero-Net Energy Upgrades:
A town-funded ($4,692,000) 1.65 MW wind
turbine (installed in Nov. 2009 and operational
by March 2010; is the Commonwealth's first
utility-scale municipal wind turbine)
An SRF/ARRA-funded ($4,865,000) 1.65 MW
wind turbine (currently under construction)
Anticipated Results:
Approximately $508,000 in annual energy savings
Since installation, the town-funded wind turbine
has generated 882,266 kW of clean energy or
the equivalent of enough power an Average
American Home for 79 years
ARRA-funded wind turbine is projected to
generate 3,624 MWh per year, thus reducing the
Town's carbon emissions by 20%
Achieve positive cash flow in first year by utilizing
Massachusetts long-term Renewable Energy
Credit incentives
Community Contact:
Heather Harper, Assistant Town Manager
(508) 495-7320; hharper@falmouthmass.us
CITY OF PITTSFIELD, MA: WASTEWATER TREATMENT FACILITY
The City of Pittsfield operates an advanced nutrient-
removal treatment facility that processes approximately
10.8 million gallons of wastewater per day. The facility
treats municipal and industrial wastes from the City of
Pittsfield and the surrounding communities.
Zero-Net Energy Upgrades:
Upgrading the aeration system from a mechanical
mixing system to a fine bubble mixing system
Performing heating and lighting upgrades
Upgrading the existing anaerobic biomass
(sludge) digestion system by installing a 195 kW
biomass cogeneration system for on-site electric
power generation
Installing a 1,575 kW solar photovoltaic system
(ground-mounted)
Anticipated Results:
Approximately $647,000 in total annual energy savings
3,263,000 kW hours of annual green power
generation from solar photovoltaic and Combined
Heat and Power [CHP] (approximately 69% total
power generation)
3,252 tons of carbon dioxide emission reductions
Community Contact:
Bruce Collingwood, DPW Director
(413) 499-9330; bcollingwood@pittsfieldch.com
TOWN OF LEE, MA: DRINKING WATER TREATMENT FACILITY
TheTown of Lee operates a surface water treatment plant
that treats and distributes more than 308 million gallons
of drinking waterfor 2,055 customers annually. The facility
currently utilizes an 80 kW hydroelectric turbine at the
plant that generates nearly 50% of its on-site electric
power needs, saving the facility $28,000 annually.
Zero-Net Energy Upgrades:
Installing Variable Speed Drives (VSDs) and
optimizing batching, premium motor, lighting,
and heating upgrades
Installing a 34 kW solar photovoltaic system on site
Optimizing the existing 80 kW hydroelectric
microturbine system to increase on-site renewable
power generation
Mass.
Anticipated Results:
Over 90% production of the plant's electricity needs
Approximately $34,000 in annual energy savings
114 kW of green power generation
153 tons of carbon dioxide emission
reductions annually
Although these upgrades were 100% funded by
ARRA, the Town of Lee would have realized positive
cash flow in the first year by combining its annual
energy cost savings with Massachusetts'existing
solar Renewable Energy Credit incentives.1
Community Contact:
Christopher Pompi, DPW Superintendent
(413) 243-5520; cpompi@town.lee.ma.us
------- |