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Michigan’s Energy Survey
Peter V. Cavagnaro, P.E. Johnson Controls, Inc.
With assistance by
Christopher Conn Michigan Department of Environmental Quality
Michigan WEA Sustainable Energy Seminar
Eagle Eye Banquet Facility - East Lansing, MI
October 13, 2016
Topics
1. Purpose of the Energy Survey
2. Energy Survey Results
3. Michigan’s WRRF Energy Baseline
4. Benchmarking a specific facility
Purpose of Energy Survey
Trend in WRRF Energy Consumption
Electricity Use and Management in the Municipal Water Supply and Wastewater Industries, Electric Power Research Institute, 3002001433, Final Report November 2013. With the Water Research Foundation
1996 EPRI Report 17.4 Billion kWh/year
2013 EPRI Report 30.2 Billion kWh/year
74% Increase
EPRI = Electric Power Research Institute
Importance of Energy to a WRRF
• Energy is one of the three major expenses involved in operating a WRRF • Labor • Chemicals • Energy
•Having a predictable and sustainable supply of energy is critical to maintaining stable rates
Importance of Energy to a Community
•Approximately 50% of the amount spent on energy by local government is for pumping and treating water and wastewater
Allocation of Energy for Water & Wastewater
Raw Water Pumping
7% Water
Treatment 17%
Water Distribution
17%
WW Collection
4%
WW Treatment
55%
Raw Water Pumping Water Treatment Water Distribution
WW Collection WW Treatment
Importance of Energy
Implementing a “Net Zero Energy” Policy at a WRRF can have a significant impact on rates and the cost of power for a community
What level of reduction is possible?
• Energy Conservation 5 – 15%
• Energy Production 20% to > 100%
2016 Energy
Survey with
Discussion
• Initiative by Michigan DEQ WRD in 2015
• Reported at 2015 MWEA Sustainable Energy Seminar
• An estimate of how much energy is used to treat wastewater in the state of Michigan is needed to make informed decisions
• Order of magnitude estimate presented in 2015
• Statewide survey initiated in 2016 to determine how much energy is used and where
Who?
2016 Energy Survey
• Online survey launched March 21, 2016
• Collected information on energy used during 2014 to establish Michigan WRRF Energy Baseline
• 24 Largest WRRF’s in MI were invited to participate
12 Responded + 4 Additional volunteers
16 Respondents total
• Facility Flows ranged from 1.9 to 670 MGD
• Participants represent 68% of total flow in MI
Information Requested
2016 Energy Survey
• Date of construction and improvements
• Facility processes
• Influent loading & flows • BOD, TSS, Ammonia, TKN
• Average Monthly
• Natural gas & electric energy – monthly
• Digester Gas production & use
• Electric Production
Please Note ….
• The numbers presented today are based on raw survey data
• The results are order of magnitude estimates
• Provides some idea as to where we are to know where to go
12
• The values will be refined as additional information is collected and methods of analysis are refined
72
48
33
89
25
53
25
00
21
72
46
62
17
24
32
86
30
34
17
09
89
7
25
84
16
75
13
56
14
13
72
1
P O N M L J K I H G F E D C B A
KW
H/M
G T
REA
TED
FACILITIES
Energy Intensity in kWh/MG
Organized in order of facility average daily flow from low to high
Compared to Wisconsin’s survey
MGD = million gallons per day Source: Water & Wastewater Industry Energy Best Practice Guidebook
Courtesy of Wisconsin Focus on Energy
0
1
2
3
4
5
6
7
8
P O N M L J K I H G F E D C B A
FACILITIES
WI Focus on Energy
Michigan Survey
WI Focus on Energy
WI Focus on Energy
Flow Range Average
Energy Use Average
Energy Use
Top Performance
Quartile
Best Practice Benchmark
MGD kWh/MG kWh/MG kWh/MG kWh/MG
0 to 1 5440 N.A. <3,280 3060
1 to 5 2503 2699 < 1,510 1650
> 5 2288 1040 <1350 1760
Compared to other benchmarks
Courtesy of Wisconsin Focus on Energy
Source: Water & Wastewater Industry Energy Best Practice Guidebook
Wisconsin Focus on Energy
NYSERDA (2008) Michigan Survey
Flow Range Average Energy Use Average Energy Use
MGD kWh/MG kWh/MG
< 1 4620 N.A.
1 to 5 1580 3402
5 to 20 1740 3023
20 to 75 1700 1756
> 75 1100 N.A.
NYSERDA (2008)
Yonkin, M., Clubine, K., O’Connor, K., Importance of Energy Efficiency to the Water and Wastewater Sector, NYWEA Clearwaters, Spring 2008
New York State Energy Research and Development Authority
Compared to other benchmarks
Electric Producers Research Institute (EPRI 2013)
EPRI 2013 (Table 5-1)
Michigan Survey
Flow Range Average Energy Use Average Energy Use
MGD kWh/MG kWh/MG
< 2 3300 N.A.
2 to 4 3000 2851
4 to 7 2400 2500
7 to 16 2000 3023
16 to 46 1700 1756
46 to 100 1700 N.A.
Ref: Electricity Use and Management in the Municipal Water Supply and Wastewater Industries, Water Research
Foundation, Electric Power Research Institute, 3002001433, Final Report November 2013.
Compared to other benchmarks
Michigan WRRF’s Energy Baseline
72
48
33
89
25
53
25
00
21
72
46
62
17
24
32
86
30
34
17
09
89
7
25
84
16
75
13
56
14
13
72
1
P O N M L J K I H G F E D C B A
KW
H/M
G T
REA
TED
FACILITIES
Energy Intensity in kWh/MG
1. Developed an equation to related energy intensity and flow
2. Applied the equation to each WRRF in the CWNS to obtain an energy intensity for each plant
3. Estimated energy use for each plant and totaled to estimate total for the state
Refine Estimate of Statewide Use
2015 est 2016 est
State of Michigan
ADF MGD 1,200 1,386
Average Energy
Intensity kWh/MG 2,300 1,189
Energy per year MWh/yr 1,007,400 821,166
Observations
• Actual energy use is between 800,000 and 1,200,000 Mega Watt Hours/year
• Online Survey allowed collection of a good amount of data
• Follow-up was needed to vet the information provided
• Ongoing effort vs. one time event
Benchmarking a specific facility or specific process
Google search …
Compared to another survey
MGD = million gallons per day
Source: Water & Wastewater Industry Energy Best Practice Guidebook
Courtesy of Wisconsin Focus on Energy
• All facilities had potential to reduce consumption
• The amount of reduction was not the same for all facilities
• The level of reduced consumption was not the same for all facilities
• Application of a generic energy intensity can impose goals that a facility cannot meet
Compared to other benchmarks
EPRI Observations on Energy Use • Normalized wastewater treatment energy use is highly flow dependent and treatment-specific
• Electric energy use intensities at treated flows in excess of about 20 MGD are fairly consistent
• For the more established treatment processes electric energy use intensities fall along a range from 1,300 to 2,500 kWh/MG
• Using more advanced systems entails a sizeable increase in electricity use.
Other factors: Organic Load & Pumping
Item Min Max
Addition of Intermediate Pumping 3% 4%
Doubling Influent Pumping (Increased Head) 6% 12%
Doubling Wastewater Organics 31% 54%
Potential Impact 41% 70%
Factors Affecting Energy Intensity
• Location (geography and weather) • Facility age, and dates of upgrades • Facility Size (energy intensity decreases with increasing
size) and ratio of ADWF to Design Flow • Equipment type and size • Strength of wastewater (COD/BOD and TKN/Ammonia) • Type of process / technology (activated sludge, trickling
filter, oxidation ditch, lagoon) • Discharge Limits • Amount of pumping • Operating Strategy • Degree of instrumentation and control • Cost of local electricity
Some WRRF Benchmark Options
• Energy Star Portfolio Manager
• Water Environment Research Foundation ENRC1
• Electric Power Research Institute
• Build your own Spreadsheet
• Works for primary, secondary, and advanced plants
• Enter data and are assigned a numeric value between 1 and 100
• Does not account for High Purity Oxygen, Incineration, or Energy Production
• Flow must be > 0.6 MGD
• Electric use must be > 100,000 kWh
• MWEA Sustainable Energy Committee setting up a Portfolio Manager site so plants can share their data
Energy Star Portfolio Manager
• Net Zero Energy Solutions for Water Resource Recovery Facilities
• Evaluated energy models of WRRF configurations • 25 “typical” baseline energy models
• 25 “best practices” energy models
• 18 “pioneering” process models
• Established common influent and effluent characteristics
• Establish benchmark by comparison to one of the process models most resembling your facility
WERF ENER1C12
• EPRI 2013 Report
• Table 5-2 estimates energy use by unit process and average daily flow rate
EPRI Estimate by Unit Process
EPRI Table 5-2
#
Units
HP of
Unit
kW of
Unit
# Units in
Operation
Hrs/Yr in
Operation
Est. Power
Consumption
kWh/yr
Percent of
Total
Raw Wastewater Pumps 3 200 149.2 1.5 8,760 1,960,488 15.10%
Fine Screens 3 1.5 1.1 2 2,190 4,818 0.04%
Fine Screen Conveyor 1 1.5 1.1 1 2,190 2,409 0.02%
Grit Removal 2 2 1.5 2 8,760 26,280 0.20%
Grit Pumps 2 10 7.5 2 2,190 32,850 0.25%
Primary Settling Basins 4 2 1.5 4 8,760 52,560 0.40%
Primary Sludge Pumps 2 20 14.9 4 2,190 130,524 1.00%
Aeration Blowers - PD 4 250 186.5 1 8,760 1,633,740 12.58%
Aeration Blowers - Centrifugal 4 300 223.8 3 8,760 5,881,464 45.29%
Secondary Settling 4 2 1.5 4 8,760 52,560 0.40%
Return Activated Sludge Pumps 4 50 37.3 4 8,760 1,306,992 10.06%
Waste Activated Sludge Pumps 3 10 7.5 2 2,190 32,850 0.25%
Disinfection System 1 130 1 4,380 569,400 4.38%
Final Effluent Peak Pumps 4 100 74.6 1 350 26,110 0.20%
Primary Sludge Thickening 4 10 7.5 4 350 10,500 0.08%
Anaerobic Digester Circulation
Pumps 4 15 11.2 4 8,760 392,448 3.02%
Anaerobic Digester Mixing 6 10 7.5 4 8,760 262,800 2.02%
Belt Press 1 0 7.5 1 2,920 21,900 0.17%
Odor Control 1 50 37.3 1 8,760 326,748 2.52%
Effluent Reuse Pumps 1 10 7.5 1 4,380 32,850 0.25%
Sludge Transfer Pumps 2 20 14.9 1 2,080 30,992 0.24%
WWTF Compressed Air System 2 30 22.4 1 8,760 196,224 1.51%
12,987,507 kWh/yr
10 MGD
3,650 MG/yr
3,558 kWh/MG
Option 4 - Build your own spreadsheet
#
Units
HP of
Unit
kW of
Unit
# Units in
Operation
Hrs/Yr in
Operation
Est. Power
Consumption
kWh/yr
Percent of
Total
Raw Wastewater
Pumps 3 200 149.2 1.5 8,760 1,960,488 15.10%
Fine Screens 3 1.5 1.1 2 2,190 4,818 0.04%
Fine Screen Conveyor 1 1.5 1.1 1 2,190 2,409 0.02%
Grit Removal 2 2 1.5 2 8,760 26,280 0.20%
Grit Pumps 2 10 7.5 2 2,190 32,850 0.25%
Option 4 - Build your own spreadsheet
Sum and compare total to consumption on energy bill
What to take away from this presentation
• A “Net Zero Energy” Policy can help control rate increases and the cost of power for a community
• The Michigan Energy Survey Data is comparable to other WRRF Surveys
Information was useful in refining the States WRRF Baseline energy use
• Benchmarks • Results are subject to number, size, and
type of facilities surveyed
• Useful for validating survey results and setting value for statewide energy intensity
• Each Facility is unique and should have its own Baseline & Benchmark
Acknowledgements
Christopher Conn Michigan Department of Environmental Quality Water Resources Division Permits Section Lakes Michigan and Superior Unit 517-230-4710
Ryan Casman Student Intern Michigan Department of Environmental Quality Kolene Allen Environmental Services City of Grand Rapids
Joseph Cantwell, PE Focus on Energy - Large Energy User Program Leidos Engineering, LLC
Brookfield, WI 53045
Thanks go to the facilities who participated in the survey
Additional Reading Kathleen Hallett Literature Review on Energy Intensities
http://dnr.wi.gov/aid/documents/eif/focusonenergy_waterandwastewater_guidebook.pdf
Additional Reading Wisconsin Focus on Energy Best Practices Guide