Priorities, Constraints and Other Issues: Energy Audits...Audit Sequence –Energy Balance Part 1 • Draw boundary (BOX) around plant • Determine all materials and energy entering

Priorities,

Constraints and

Other Issues:

Energy Audits

October, 2016

Session’s Agenda

• Priorities, Constraints, Energy?

• Audit steps and best practices

• Consumption Pie Chart

• 4 plants 4 stories

• Energy audit do’s and don’ts

• Conclusions

Juggling Priorities, Constraints and Other

Issues

• Energy

Management….

Where does it fit in

your priority list?

Priorities?

• Worker Safety

• Permit Compliance

• Community/Public

Health

• Cost Control

• Public Image

• Approval of Agency

Directors

• Incentives

• No night-time calls

• Plant reliability

• O&M considerations

• Energy Management

• Environmentally

friendly

• Staffing

• Long-range Planning

• Utility Company

Relationship

• Fitness Facilities

Energy Efficiency/ Renewables!!!!

• Typically down on the

priority list!

• Potential conflict with

permit requirements

and past operating

practices

• Large portion of

facilities do not see

the utility bills

• Often seen as difficult

• Utility rate structure

and $$$$ a budget

item annual increase.

• Pass increases to

rate payers

• Renewables; new

technologies and

$$$$

• What is IT?

• Why is IT?

• How can I see IT?

• Understanding IT

• Using IT

• Benefitting from IT

THE BUILDING BLOCK STORY

WHAT IS IT?

PLANT

(ENERGY UTILIZATION

INFORMATION)

PLANT

BUILDING BLOCKS OF A TREATMENT PLANT

PLANT LIGHTING LOADI-7

I-7

I-7

I-7 I-7 I-7

WHAT IS IT? (ENERGY UTILIZATION INFORMATION)

• Instantaneous Utilization (kW)

• Amount used over a specific period

(KWh/period)

• Peak Use (Highest KW over a specific period)

• Historical Data (continuous metering)

• Factors involved in YOUR ELECTRIC bill!


CLARIFIERS

SEPARATORS

&

CENTRIFUGES

SCREENS

PUMPS

Why Complete an Energy Audit?

• Potential energy and cost

savings

• Policy mandates

• Identify improvements

• Identify fund alternatives

• Understand your energy

use and costs

• It’s under your controlPLANT

Benefits of Energy Audit?

• Improve understanding of processes

• Bridge energy use and accounting

• Gain comprehension of utility bills and

charges

• Clarity of energy use and effects

• Improve resource utilization

• Enhance relationship with utility provider

• Improve relationship with rate payers

Benefits of Energy Audit?

• Recognize your successes

• Goal development

• Reduce operating costs

• Prepare for a renewable future

• Three legged stool: energy efficiency,

energy conservation and renewable

energy generation

STA

RT

FIN

ISH

Energy Audit - Road Map

Audit Sequence – Define Type

• Many types of energy audits

– Technology specific i.e. lighting,

compressed air, controls automation

– Process specific i.e. disinfection, hydraulic

capacity

– Other…

• Commercial facility energy auditing rules

of “thumb” typically do not apply

• Focus and goal(s)

Audit Sequence – Define Level

• Three basic levels of energy audits

– Level I

– Level II

– Level III

• Commercial facility energy auditing rules

of “thumb” typically do not apply

• Focus and goal(s)

Audit Sequence – Team Selection

KEY PLANT

STAFF

KEY PLANT

STAFF

AUDITORSAUDITORSPLANT

MANAGEMENT

PLANT

MANAGEMENT

UTILITY

PROVIDERS

UTILITY

PROVIDERS

Expertise in:• Infrastructure

• Energy

• Sustainable solutions

Clear Focus & Goals

Managers, Accounting, & Plant Operators• Understanding of plant processes

• Regulatory requirements

• Health & Safety

Onsite

account representative

“Long Range Vision”• Ultimate responsibility

• Capital management

• Financial planning

Audit Sequence – Pre Audit Info Gathering

• Site plan

• All utility bills

• Utility schedules

• Process flow diagram

• Electric diagrams

• Detailed equipment list with installation dates

• Pre site visit analysis

SecondaryClarifiers

AnaerobicDigesters

KaneoheMCAS Effluent

Influent Pumping(Onsite Pump

Station)

Headworks

Step Screens /Grit Removal

EffluentPump Station

To Outfall

Sludge Dewatering (Centrifuges)

Landfill

PrimarySedimentation

Fixed Film(Biotower)

AeratedSolids

Contact

UltravioletDisinfection

Dissolved AirFlotation Thickeners

• Reconcile energy use

• Create baseline

• Develop energy

accounting assumptions

• Minimum 2 yrs of analysis

• Local rate schedules

• Determine demand

sensitive operations

Audit Sequence – Utility Bill Analysis

Understanding the Energy Game!

• Fully understand

the utility rate

schedules and

associated fees!

• Consult with utility

account

representative and

ask questions.

• What charges are

associated with

use (kWh) and

time-of-use (TOU)?

• What is the billing

cycle?

Tracking and Management of Data

• All games have

rules!

• Knowing the game

and rules helps

ensure the

decisions will make

a difference

WWTP Monthly Electric Energy Cost Breakdown

$0

$25,000

$50,000

$75,000

$100,000

$125,000

$150,000

$175,000

$200,000

Mar

-08

Apr-0

8

May

-08

Jun-

08

Jul-0

8

Aug-

08

Sep-

08

Oct-0

8

Nov-

08

Dec-

08

Jan-

09

Feb-

09

Months

Co

sts

($)

Electric Use Portion Electric Demand Portion

Audit Sequence – Electric Demand Sensitivity

• Demand can be 15-40% of your elec. costs

> 33%

WWTP Monthly Electric Demand - 30 Minute Interval Data

2,500

3,000

3,500

4,000

4,500

Ele

ctri

c D

em

and

(K

w)

Audit Sequence – Demand Sensitivity Cont…

+300 kW Spike

• Determining your demand spikes can save $

• 300kW over typical peak demand = $50k/yr

3,400 kW

3,700 kW

WWTP Electric Demand – 30 Minute Interval Data

Audit Sequence – Energy Baseline

Power Generated

> Power Used

0100200300400500600700800900

1000

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

kW

h/M

G

Power Used Power Generated

• Goal development – where are you?

• Your personal “Benchmark”

• Framework for strategic planning

• Where dreams start to become reality!

Audit Sequence – Energy Benchmark

• Benchmark analysis allows industry

comparison on a “macro level”

• Factor in local considerations

• Options include:

– Self comparison

– Regional comparison

– National comparison

Audit Sequence – Onsite Info Gathering

• Introduction of participants

• Review of materials

previously collected and

analyzed

• Virtual operations review

• Conduct site walk

Audit Sequence – Onsite Walk Activities

• Evaluate plant metrics

& process variability

• Analyze historical &

seasonal events

• Regulatory permits or

operational limits

• Review site metering

and monitoring


• Interview operators

– For their perspective

– Unique plant dynamic

– Control strategies

– Operating schedule

• Observe and record current conditions

• Photographic documentation


• Inspect and verify equipment information

– Operating conditions

– Operating schedule

– Nameplate data

– “Demand impact”

– Record meter reads

• Conduct exit meeting

• Thank all participants

Audit Sequence – Analysis of Information

• Organize information captured

• Reconcile energy use

• Develop energy baseline

• Determine energy accounting assumptions

• Continue to collect site information

• Create equipment load and use list for

finalizing energy balance

EFFLUENT

OUT

SOLIDS

OUT

WASTEWATER

IN

Audit Sequence – What Energy Balance?

??

??

CHEMICALS

IN

PLANT

Audit Sequence – Energy Balance Part 1

• Draw boundary (BOX) around plant

• Determine all materials and energy

entering and exiting the BOX

– Influent flow into and through plant

– Energy and fuel into plant

– Potable water into plant

– Effluent flow out of plant

– Solids out of plant

– Self-generated energy out of plant

WASTEWATER

IN

EFFLUENT

OUTENERGY &

OTHER FUELSEMISSIONS CHEMICALS

IN

RECLAIM

WATER

SOLIDS

OUTPOTABLE

WATER

Audit Sequence – Your Energy Balance!

PLANT

Developing the Energy Use Pie Chart

• Determine total energy

used per month (kWh).

• Develop an equipment

list for all processes.

• Estimate a load profile

for each process area

(e.g. 1 pump operating

at 75% load)

• Estimate actual hp

• Estimate number of

hours per month for

each piece of

equipment.

• Convert hp to kWh

using simple

HP*0.75= kWh

• Summarize total kWh

and compare to

monthly utility bill

Pie Chart Development Part 2

• If within 10% excellent;

if > 10% select larger

loads for more detail

energy estimation.

• Techniques for

enhanced power use

metric:

– AMP draw

– Hobo monitor

– Power Quality Meter

(PQM)

• Conversion of data

into pie chart or

tabular format

• Check utility bills for

seasonal fluctuations

and cross check load

profiles to account for

variations (e.g. wet

season… more

pumping)

Audit Sequence – Energy Balance Part 2

• Develop baseline metrics (e.g kWh per MG)

• Analyze energy use for each process type

10%

54%

5%

24%

7%

PLANT #1 PLANT #2

Audit Sequence – ECO Development

• What’s an ECO?

• ECO = Energy Conservation Opportunity

• Further evaluate findings from Audit Phase

through… WHAT is happening Inside the BOX!

• Ask the investigative questions!

– Who? What? Where? When? Why? How?

• Typically start with the larger energy use areas

first “80/20 rule”

• Select potential list of ECOs

Energy Analysis – ECO Development Process

• Examples of “Investigative”

ECO questions– “Why are blowers operating 24/7?”

– “Why are UV and chlorine disinfection

required prior to discharge?”

– “Why are four primary tanks in service when

influent flow only requires two?”

– “How efficient is a constant pressure pumping

system with variable demands?”

– “If odor control is needed only 30 hours per

week, why is the odor control system in

operation 24/7?”

– “How often does sludge dewatering occur?”

Energy Analysis – ECO Screening Process

• List all ECOs

• Estimate of energy savings

• Identify capital improvement requirements

• Review ECO viability (non-energy factors)

• Select ECOs for further development

Energy Analysis – Example ECOs

• High efficiency motors

• Variable operation

motors and drives

• Process optimization

• Process replacement

• Schedule modifications

• Water reuse

Each Facility is Unique!

• Every facility is unique with ever-changing

and uncontrollable parameters

• Plants have specific process requirements

• Site specific permits, restrictions, regulations

and rate structures

• Each plant is located in a unique setting

providing potential opportunities and specific

issues to overcome

Considerations associated with auditing

infrastructure facilities:

Comparing “Treatment Plant Unique DNA”

PROCESS KAILUAHILO WAIMEAKIHEI

Influent Pumping

Screening/Grit Removal

Primary Sedimentation

Fixed Film (Biotower)

Aeration Basins

Solids Contact

Advanced Water Treatment

Chlorine Disinfection

Ultraviolet

Effluent Pumping

Common Outfall Pumping

Comprehensive Odor Control

Thickening

Aerobic Digestion

Anaerobic Digestion

Digester Gas Utilization-Heating

Dewatering-Centrifuge

Dewatering-Solar Drying

Landfill

Composting

Water Reuse

FOG Program

Digester Gas-Cogeneration

Secondary

Where is the Energy Used?

39%

31%

7%

8%

7%

5%3%

Influent Pumping

Aeration

Internal Plant Pumping

Effluent Pumping

UV Disinfection

Odor Control

Digestion

Reclaim Water Treatment

Mechanical Dewatering

Adminstration/Maintenance

Balance of Plant

10%

8%

10%

9%

18%

22%

9%

3%

8%

39%

31%

7%

8%

7%

5%3%

Influent Pumping

Aeration


Effluent Pumping

UV Disinfection

Odor Control

Digestion




Balance of Plant

• Fixed film plants (Biotowers)

• Comparison energy utilization pie charts

Kailua, Oahu Hilo, Hawaii

Where is the energy used?

• Activated sludge/mixed liquor facilities

40%

5%20%

9%

7%

11%

3%

1%

2%

2%

Influent Pumping

Aeration


Effluent Pumping

UV Disinfection

Odor Control

Digestion




Balance of Plant

9%

3%

13%

4%

44%

27%

Kihei, Maui Waimea, Kauai

39%

31%

7%

8%

7%

5%3%

Influent Pumping

Aeration


Effluent Pumping

UV Disinfection

Odor Control

Digestion




Balance of Plant

Preliminary ECO Results – Hilo WWTP

• $125,000-160,000/yr cost savings

• 20-25% energy and water savings

• 35-40% electrical energy reduction

• 6 Major ECO recommendations:1) Reduce dewatering system odor control fan operation

2) Modify number of primary clarifiers on line

3) No.2 water pumping system improvements

4) Electrical demand management

5) No.3 water pumping system improvements

6) Replace low efficiency motors w/ high efficiency units

Preliminary ECO Results – Kailua WWTP

• $250,000-$400,000/yr cost savings



• 5 Major ECO recommendations:1) Replace existing UV with high-efficiency system

2) Improve plant electrical grid

3) Install new digester gas boilers

4) Biogas cogeneration (500 kW)

5) Lighting system retrofits

Preliminary ECO Results – Kihei WWTP

• $250,000-$325,000/yr cost savings

• >25% energy savings by plant prior to audit

• 10-15% additional savings from audit

• Overall 30-40% electrical energy reduction

• 3 Major ECO recommendations:1) Reclaim water storage and pumping improvements

2) Compressed air system replacement


- Aeration blower upgrades (recently installed by plant)

- UV system replacement (recently installed by plant)

Preliminary ECO Results – Waimea WWTP

• $15,000-$25,000/yr cost savings



• 3 Major ECO recommendations:1) Effluent pumping modifications

2) Aeration blower system replacement


Audit Sequence – Do the $ make “sense”?

Do the “Cents” really make “sense”?

• Economic viability

• Consistent with health & safety

• In line with regulatory requirements

• Satisfy plant reliability requirements

• Meet long-term strategic planning

• Is funding available

0

1,000

2,000

3,000

4,000

5,000

Hilo

Kailu

aKi

hei

Wai

mea

KW

H/M

GA

L

0

1,000

2,000

3,000

4,000

5,000

Hilo

Kailu

aKi

hei

Wai

mea

KW

H/M

GA

LFuture Plant Energy Baselines = Opportunity

Current Baseline

Future Baseline

35-40%

Baseline

Reduction

20-30%

Baseline

Reduction

30-40%

Baseline

Reduction

20-30%

Baseline

Reduction

Energy Audit – Do’s and Don’ts

• Three key’s to effective auditing:

“Information, information, & information!”

• Enlist team concept with plant personnel

actively engaged in auditing

• Look beyond the numbers

• Understand local requirements and

prohibitions

• Priorities, Constraints and Issues?

Energy Audit – Do’s and Don’ts Continued…

• Confirm assumptions

• Evaluate “aggressively” but “keep it real”

• Make the auditing process a learning

experience for all participants

Conclusions!

Good information + Right audit team

=

Enhanced energy utilization +

Increased operational understanding + $$$

• Learn from the experience

• Better resource utilization awareness

• Energy / resource management improvements

• Save a couple of “cents” along the journey!

Questions and Discussion

Don King, PE

Senior Energy &

Sustainability Engineer

[email protected]

(760) 310-8544

Documents

Priorities, Constraints and Other Issues: Energy Audits...Audit Sequence –Energy Balance Part 1 • Draw boundary (BOX) around plant • Determine all materials and energy entering