Common Sense Approaches to Saving Energy and Money

Conrad Meyer Technical Manager - WRP

Improving Energy Management

• Tracking and Understanding Energy Use – Electric Utilities Terms & Rates

– Energy Baselines

– Benchmarking Energy Use and Performance

• Energy Assessments – Energy Use by Area

– Common opportunity Areas

– Technical & Financial Analysis

– Help and Resources

Benefits of Tracking Energy Use

• Identify Opportunities for Energy Savings

• Provides a Baseline for Measuring Improvements in Performance

• Trending Energy Performance Over Time Reveals Operating Alternatives

• Uncovering Best Practices for Superior Energy Performance – Equipment and Technology Comparisons

Energy Measurements

• Electrical - Demand and consumption.

– Demand – kilowatts (kw) – think of as rated connected horsepower – how much horsepower for given speed, rate of flow?

– Consumption – kilowatt hours (kwh) – use of connected horsepower over time – how fast will it go and how long traveled at given speed?

• Energy benchmark – kwh/MG how many miles per gallon at a given speed?

Energy Measurements - Kw & kwh

• Lights – watts or watts/1000 = kw

• Motors – horsepower x 0.746 = kw

• Direct Heat/Hot Water = kw

• Plug Ins – computers, printers, heaters – watts or watts/1000 = kw

• Quality Control Instruments = watts

• Btus/hr x 0.000293 = kw x 1 hr = 1 kwh

• 1000 watts = 1 kw x 1 hr = 1 kwh

How Much Does It Cost?

Are you on the right rate schedule?

Example: Billing Information Given: 1.5 MGD WT/WWT Plant

• Billing Demand – 250 kw, Contract Demand 350 kw

• Consumption – 130,000 kwh/month, 3Ø, PF > 0.85

Re-Sale Power - Rate Schedule

• Customer Charge - $ 50

• Demand Charge - $17.15/kw x (250-50)kw = $3,430

• Energy Charge – 15,000 kwh x 11.719¢/kwh + (130,000 – 15,000) x 6.696¢/kwh = $9,458.25

• Month’s Electricity Cost - $12,938.25 + 2.83 % tax

Have you calculated your energy cost?

Demand Reduction Savings

• Most Significant Means 1. Operation Control and

2. Time of Use Contracting

Requires : – Inventory of Large Motors

– Time of Use Operational Flexibility

– Knowledge of Utility Opportunity Windows

• Receive Double Dip Savings – Consumption and Demand Savings

Time of Use (TOU) Contracting

• Electricity Cost Based Upon Reduced Rates for:

– Time of the Year

– Time of the Week

– Time of the Day

• Can Daily, Weekly, and Seasonal Operation be Controlled by Process Flexibility with Varying Throughputs? Storage Buffers Exist? Catch Up Capacity Good? Knowledge Indicators in Place?

Windows of Opportunity - TOU

Demand Shifting Example

• 300 kw with 50 kw Shifted to TOU Window

Service

Customer Charge $

Demand Kw $

Energy Kwh $

Total $/Month

SGS Utility B < 1000 Kw

$21 $4.89 x 300 kw

= $1,467

130,000 kwh x $0.0703/kwh =

$9,139

$10,606

SGS Utility B TOU

$21 $7.48/kw x 250 kw + 300 kw x

$1/kw = $2,170

On Peak 42,900 kwh x $0.0606 + Off Peak 87,100 kwh x $0.0485 =

$6,824

$9,034

Savings $1,572/Mo

Effective Energy Management

• Conduct an Energy Survey

• Calculate the Demand and Consumption of the Largest Motors

• 100 Hp Motor May Cost $50,000/yr To Run Continuously

• Use Motor Master® if More Than 10 Large Motors – Free program download - US Dept. of Energy

– http://www1.eere.energy.gov/manufacturing/tech_assistance/software_motormaster.html

Motor Master® Software 4.01 Repair vs. Replace Decision Basis

Energy Benchmarking

• EPA Energy Star® Portfolio Manager - Water/Wastewater Treatment Plants

• Rating System – 1 to 100

• http://www.energystar.gov/index.cfm?c=water.wastewater_drinking_water

Energy Star® Benchmarking

• Compares energy intensity of a single facility with similar facilities nationwide

• Kbtus/GPD = Total annual source energy/avg. GPD

• Input Data – Zip code, avg. influent and effluent flow, avg. influent and effluent BOD5 facility design flow, Processes Present – Nutrient removal, trickle filtration, etc.

• Performance = Actual source energy use intensity(EUI)/energy intensity predicted by Energy Star Model Number 1 to 100

Pump Size vs. Efficiency

• Impeller Sized for Best Efficiency

Point (BEP) Head & GPM? • Are You in the Zone? • Single 1,000 gpm Pump @ 400 ft. Head Cost $66,000 Annually At $0.07/kwh at 70% Pump Efficiency and $61,600 at 75% Efficiency

Pumping – Best Efficiency Point (BEP)

BEP

Where You Operate Is Important! Costly

Cost Of Throttling Design Capacity

• BEP design flow range @ 83% efficiency, 60 Bhp

– Min. flow – 1050 gpm @ 175’ head

– Max. flow – 1250 gpm @ 160’ head

• Throttle capacity back to 600 gpm, what does it cost?

• Bhp = 600 gpm x 190’/3960 x 0.70 eff. = 41 x 0.746 kw/bhp = 30.6 kw x 8760 hrs/yr = 267,833 kwh x $0.07/kwh = $18,775

• Pump design has 60 Bhp motor that costs $27,446/yr to operate but needs only 40 Bhp motor so throttling is costing $27,446 - $18,775 = $8,692/yr about $1/hr

11.1

0.2 0.4

4.7 1.4 0.3

3

0.3 8.6

0.4

67

2.1

Energy Use By Water Treatment Process 10 MGD - Per Cent Energy Use

Raw Water Pumping

Coagulation Feed

Polymer Feed

Rapid Mixing

Floculation

Sedmentation

Gravity Filtration

Surface Wash

In Plant Pumping

Hypo Feed

Fin. Water Pumping

Admin, Lab, Maint.

Cherokee Water Treatment Plant Intake Pump House Upgrade

Existing

• 2 – 130 HP premium efficiency

• Certified Pump curve operating Point 80% efficiency @ 2100 gpm @160 ft head

• Operating one pump at a time

• Average Actual Pumping 972 GPM

• Flow controlled by throttling the discharge of the pump

Proposed Upgrade

• Retrofit the two pumps with MagnaDrive - adjustable speed control

• Cost Savings $33,000 annual ($0.072/kWh)

• Installed cost $30,000 for both motors (under construction)

• Considering broader solutions ($800k)

Town of Valdese WWTP Influent Pump Upgrades, 2011

Existing

• Designed for 7.5 MGD

• Operating Average 2.0 MGD

• 2- 200 HP pumps w/1st generation variable frequency drives (VFD)

• Energy use: 300,906 kWh/yr

• Energy demand:132 kW peak

• Significant maintenance issues due to oversize

Upgrade

• 2 – 75 HP with VFD

• Energy Use: 213,113 kWh/yr

• Energy Demand: 50.2 kW peak

Savings:

• Greatly reduced maintenance issues and costs

• 87,793 kWh/year

• $7,900/year

• Project Cost: $120,000

Town of Mars Hill Plant Facility Upgrades W&WWTP

Description: Upgrades 2012

• Lighting: T-8 upgrade

• HVAC Mini split systems replace with single Heat Pump

• Electric to Gas fired IR Heaters

• Overhead door: R8 Insulation with seals

• Hot water system 80 gal to 40

• 1,500 sf WWTP

• 2,780 sf WTP – lab and tank room

Energy Savings

• 5350 kWh/year WTP

• 51 MMBTU Propane

• 601 kWh hot water

• 7.5 MMBTU – WWTP

• All energy savings projects were bundled together and scoped at 3.5 year payback

Other Energy Savings Opportunities

• Lighting – T12’s to T8’s, LED Yard Lighting

• IR Heating vs. Unit Propane Heaters

• Heat Pumps – SEER > 14

• Solar – Hot Water

• Programmable Thermostats

• Occupancy Sensors

• Central Controls

Recap -Energy Savings Result From:

• Understanding Process Potential – Energy Assessment of Operations and Equipment

• Comparing to Best Practices – Benchmarking

• Life Cycle Analysis of Cost with Efficiency Gains

• Establishing Best Operating Points

• Evaluating Utility Rate Schedule Options with Demands and Consumption Processes

• Tracking Energy Use and Comparing to Target Performance Criteria

Know your state resources

WASTE REDUCTION PARTNERS

• Providers of Water, Energy, and Solid Waste Assessments

• Evaluations and Audits for Industrial, Commercial and Institutional Customers • Generally no cost, confidential, and non-regulatory

• Technical Assistance

• Contracted Services

• Statewide Staffing

• www.wastereductionpartners.org

• Partnership Program with NC Div. of Environmental Assistance and Outreach

Commercial / Industrial Water Assessments

• Waste Reduction Partners (WRP) conducts CII water audits in the state of North Carolina

• Auditors go on site to use customer information to generate historical performance patterns and recommend practical efficiency solutions

• Retired team of volunteer Engineers, Scientists and Executives keeps costs low, experience high

• WRP can work with Water Utilities or end customers

• Report supplied to customer and utility outlines water use history, effective recommendations, and financial pay back

Annual Results Comparing Two Demand-Side Strategies

Strategy Type

Utility Cost

Annual Gallons Saved

Cost Per CCF Saved

High Efficiency Toilet Rebate @ $30

$15,000

4,315,662

$2.60 / CCF

Waste Reduction Partners I.C.I. Audit Program

$15,000

7,480,500

$1.50 / CCF

Identifying Opportunities: Basics of Conducting an Energy Audit

• Scope • Energy/utility bill review – Before site visit

• Plot the usage data – does it make sense? • Check rate schedule – other “add ons” • Benchmarking

• Have the right people on the team • Data collection – on site • Target Energy Uses

• Process/motors, HVAC, lighting

• Getting the questions answered • Recommendations • Financial analysis – cost, savings, payback

Site:

Building: (Name,

year built)

Site Contact -Title

Name:

Phone:

E-mail:

County:

Use (Office, etc.)

Floor Area: (GSF)

Street Address:

Mailing Address:

City:

State:

Zip Code:

Surveyor Name:

Team:

Survey Date: Client - Please complete the top

Survey Time: of this page and pages 2 and 3

The section below is completed by WRP assessor.

Baseline Energy Data (See Annual Energy Consumption Worksheet):

Total energy index:

Water/sewer cost: $0.00 Per year

Gallons per Occupant: #DIV/0!

Gallons / sf #DIV/0!

$0.00

Dom hot water

Utilities supplied to bldg. (Enter 1 if

present, 2 if present and metered):

Gallons per year

0

#DIV/0!

Propane

Steam

Total water use:

After-hours usage/year -

Heating hot water

Chilled water

# of floors

# of occupants

Hrs. occupied per week

#DIV/0!

Total energy consumed:

Total energy costs:

Electric

Dom cold water

Natural gas

Oil

Total energy cost index:

0

Million BTUs of energy per year

kBTU/sq. ft. per year

Per year

Total Energy Cost

After-hours usage/year -

Administration and Energy Conservation Measures (ECM) Survey

USI Checklist

Month Year Water H2O / SewerUsage Cost Usage Cost Usage Cost Usage Cost

KWH $ Therms $ Units $ Gallons $

July 2008

August 2008

September 2008

October 2008

November 2008

December 2008

January 2009

February 2009

March 2009

April 2009

May 2009

June 2009

12-month total 0 0 0 $0.00 0 0

Square footage:

CONVERSION TO BTU EQUIVALENTS

Fuel totals

0 x 3,413 BTU/kWh 0

0 x 140,000 BTU/GAL. 0

0 x 100,000 BTU/THERM 0

Propane - 0 x 92,000 BTU/GAL. 0

0

#DIV/0!

#DIV/0!

#DIV/0!

Fuel oil - gallons

Natural gas - Therms

ANNUAL ENERGY AND WATER CONSUMPTIONElectricity Natural Gas Other Fuels

Million BTU's

kBTU/SF

0

Electricity -kWh

Per Sq. Ft.

Million BTU'sTotal energy use

Cost per million BTU

Million BTU's

Total Energy Index

Total Cost Index

Million BTU's

Million BTU's

Million BTU's

2,232

2,119

1,955

1,705 1,644

1,475 1,476 1,426 1,401

1,774

2,036 1,960

162

178 172

165

137

124 126

134

126

177 174

180

0

20

40

60

80

100

120

140

160

180

200

0

500

1,000

1,500

2,000

2,500

Jul-11 Aug-11 Sep-11 Oct-11 Nov-11 Dec-11 Jan-12 Feb-12 Mar-12 Apr-12 May-12 Jun-12

Act

ual

KW

kWh

/Day

Average Electricity Usage and Demand

kWh/Day KW Demand

Roof type

(check one) B1. Metal Composite Membrane Other

Roof color

(check one) Light Dark

B2.

B3.

B4.

B5.

B6.

B7.

C1.

C2.

C3.

C4.

C5.

C6.

C7.

C8.

C9.

C10.

C11.

C12.

C13.

Is roof insulated?

Are thermal windows used? Low-e?

Are windows kept closed in conditioned spaces?

B. Building Envelope

Can lighting be controlled in perimeter rooms to make use of day light?

Have T-12 fluorescent lamps been replaced with T-8?

Is fluorescent task lighting used to minimize background lighting?

Have beverage and snack machine lights been removed?

Are procedures in place to purchase the most energy efficient equipment?

Are overhangs present on east west facing windows?

Are interior shades present and adjusted to allow daylight and reject solar heat gain?

Have energy conservation decals been placed on l ight switches?

Are occupancy sensors util ized?

Are computers using power-save feature?

Have all incandescent lamps been replaced by CFL's?

Are all electric exit l ights of LED type?

Do exterior l ights turn off during daylight hours?

Have space heaters been eliminated?

Has High-Bay T-5 lighting been evaluated for use in high ceiling areas (warehouses, gyms, auditoriums, etc.)?

C. Lighting and Electrical Systems

Is weather stripping on windows and doors present and maintained?

K1.

1

2

3

4

Simple payback:

Simple payback:

Annual potential savings:

Annual potential savings:

Annual potential savings:

Cost to implement:

Simple payback:

Cost to implement:

K. Recommendations

Cost to implement:

Simple payback:

Annual potential savings:

List top ECM recommendations (include estimated potential savings when possible). Indicate if building is a candidate for

performance contracting.

Cost to implement:

Detailed Assessment Report – Example Summary

Recommendation Cost Savings Investment Cost Payback Period

HVAC/Building Envelope

Set back, Set Forward Temperature Controls $5,257 $3,000 6.8 months

Variable Speed Air Handler Fan Drives $1,721 $3,175 1.8 years

Lighting

Reduced Lighting Levels $9/lamp/yr 0 Immediate

Motion Sensors $396 $1,231 3.1 years

Metal Halide Lamps $2,645 $1,922 8.7 months

LED Exit Lights $176 $70 4.7 months

T-12 Light Replacement $192 $700 3.6 Years

Computers

Sleep/Hibernate Controls $3,825 0 Immediate

Totals $14,212 $10,098 9.2 months

Summary of Energy Benchmarks

Total Energy Consumed 1,597 Million Btu / yr

Total Energy Index 51.5 kBtu / sq ft / yr

Total Energy Cost: $33,615 / yr

Total Energy Cost Index: $1.08 / sq ft / yr

Estimated Annual Energy Savings, $/yr

Energy, Water & SW Savings $4,459

Energy Savings

MMBTU / year

kWh/yr

119.96

32,500

Est. Annual Emissions Reductions, lbs/yr Carbon Dioxide (CO2)

1.19#CO2/kWh * 32,500kWh/yr = 38,675

Nitrogen Oxides ()

0.00293#/kWh * 32,500kWh/yr = 95

Sulfur Oxides (SOX) 0.00761#SOX * 32,500kWh/yr =

247

Detailed Assessment Report - Examples

Savings – Switching of hallway lights

Estimated hours lights could be switched off: Weekends hrs = 10 hrs/day X 2 days X 52 weeks = 1,040 hrs. Schools out hours = 10 hrs/day X 5 days X 10 weeks = 500 hrs. Total hours = 1,040 + 500 = 1,540 hrs. Cost Savings = 3 hallways X 23 fixtures X 75% switched off X .112 kwd/fixture X 1,540 hrs/year = 8,926 kWh X $.084 kWh = $750 Yr.

Costs

Costs = TBD. A very rough estimate is $400 per hallway, or $800.

Payback Period = $800/$750 = 13 months

WRP Contacts

WRP - Land-of-Sky Regional Council

WRP - Triangle J Council of Governments

339 New Leicester Hwy, Suite 140 Asheville, NC 28806 828-251-6622 wrp@landofsky.org Russ Jordan, WRP Energy Manager Terry Albrecht, WRP State Director

PO Box 12276 Research Triangle Park, NC 27703 919-558-2702 wrp@tjcog.org Conrad Meyer, Technical Manager Christal Perkins, Program Administrator

www. wastereductionpartners.org

Backup Slides

Savings Opportunities

• Large Motor Efficiency – 85% to 95%

• Centrifugal Pumps – Operating Points

• Capacity Control – Throttling vs. Variable Frequency Drives

• Treatment Optimization – Aeration, DO

• Recirculation / Processing Volume Reduction

• Demand Control

Motors Cost of Operation

• The Energy Policy Act (EPACT) of 1992 mandates that motors up to 200 hp, 3Ø, General Purpose service manufactured after Oct. 24, 1997 must meet minimum efficiency levels.

• Cost to Operate at $0.07/kwh and 8760 hrs/yr

Motor

Efficiency 50 hp 75 hp 100 hp 200 hp

Pre EPACT

$24,497 $36,266 $48,244 $95,565

EPACT $23,891 $35,418 $47,224 $93,553

NEMA PREM.

$23,512 $35,082 $46,480 $92,772

Getting to the Pump’s Best Efficiency Point

• Impeller Trimming • Control Valve Throttling • Jockey Pumping • Variable Speed Drive – Steep Pump Curve Only • Pump Software for Analysis

http://www1.eere.energy.gov/industry/bestpractices/software_psat.html

• Does Operation Require Catch-up and Slow-down Capacity? How Often?

• Yes – VFD on Smaller Pump • No – Impeller Trimming to Meet BEP