Conducting Successful Energy Audits for Both Water and Wastewater Utilities By: Rich Atoulikian, HDR

Size: px

Start display at page:

Download "Conducting Successful Energy Audits for Both Water and Wastewater Utilities By: Rich Atoulikian, HDR"

Horatio Strickland
5 years ago
Views:

3 Energy Consumption/Opportunities for Municipal Utilities Energy Savings Approaches Cultural Challenges Case Studies

4 Energy Consumption/Opportunities for Municipal Utilities Energy Savings Approaches Cultural Challenges Case Studies

5 U.S. MUNICIPAL WATER/WASTEWATER SYSTEMS Consume about 75B KW/Yr Water ~ 60% Wastewater ~ 40% Approximately 3 to 4% of national sales

6 REGULATIONS ARE WORKING AGAINST US More Stringent Regulations Nutrient Removal Toxins DBPs PFOS/PFAS.and there s more coming! Higher Operating Costs Increased Greenhouse Gas Emissions Consent Decrees

7 AS AN INDUSTRY, WE SHOULD BE THINKING ABOUT Energy Recovery Improving Energy/Operating Efficiency o Energy Audits o Energy Savings Plans

8 OPPORTUNITIES EXIST FOR ENERGY RECOVERY WATER AND WASTEWATER

9 OPPORTUNITIES EXIST FOR ENERGY RECOVERY IN WASTEWATER 544 POTWs Anaerobically Digest CHP would Produce 340 MW of Electricity Renewable Natural Gas is also an option

10 ENERGY AUDITS LEAD TO. IMPLEMENTABLE ENERGY SAVINGS PLANS

11 Energy Consumption/Opportunities for Municipal Utilities Energy Savings Approaches Cultural Challenges Case Studies

12 STEPS TO SUCCESSFUL ENERGY PLAN DEVELOPMENT

13 WATER UTILITY: SOURCES OF ENERGY CONSUMPTION Pumping o Raw Water and Finished, o Other (Filter Backwash, Membranes, etc. Sludge Collection/Residual Handling Filter Backwash Air Scour Buildings Other Reference: Capital Region Water

14 WASTEWATER UTILITY: ENERGY CONSUMPTION SOURCES Chlorination 0.27% Belt Press 3.91% Anaerobic Digestion 14.24% Gravity Thickening 0.06% Lighting & Buildings 8.14% Wastewater Pumping 14.26% Screens 0.02% Grit 1.36% Clarifiers 3.15% Return Sludge Pumping 0.46% Aeration 54.12% * Based on WEF Manual of Practice 32 Reference: WEF Manual of Practice

15 STEPS TO SUCCESSFUL ENERGY REDUCTION

16 PATH FORWARD BEYOND THIS AUDIT Organizational Change

17 Energy Consumption/Opportunities for Municipal Utilities Energy Savings Approaches Cultural Challenges Case Studies

CULTURAL CHANGE MANAGEMENT SOME SIMPLE RULES Utility Leadership Must Lead Engage the Organization Multiple Times, In Depth Compelling Reasons For Audit

18 CULTURAL CHANGE MANAGEMENT SOME SIMPLE RULES Utility Leadership Must Lead Engage the Organization Multiple Times, In Depth Compelling Reasons For Audit Must Be Clear Benchmark Current Energy Consumption Achieve Early Successes Understand Process and Physical Constraints Set Goals/Measure Progress Against Them

19 CASE STUDIES

20 CASE STUDY: CAPITAL REGION WATER Drinking Water o (~60,000 people) Wastewater o (~120,000 people) Stormwater o (~50,000 people)

21 CRW - DRINKING WATER Sources DeHart Dam & Reservoir; Susquehanna R. Intake and Pump Station 20 MGD Dr. Robert E. Young Water Services Center Finished Water Reservoirs 40 MG storage In-line hydro-turbine

22 CRW - WASTEWATER 38 MGD Advanced Wastewater Treatment Facility BNR upgrade completed in 2016 Solids improvements underway Cogeneration process provides building heat and electricity 4 Pump Stations in the Collection System

Energy Conservation Project Need Establish a baseline for current energy consumption Reduce energy consumption Reduce operating cost Increase process optimization Identify/Evaluate Viable

23 Energy Conservation Project Need Establish a baseline for current energy consumption Reduce energy consumption Reduce operating cost Increase process optimization Identify/Evaluate Viable alternatives Technically Culturally Financially Develop a program that incorporates energy saving measures and plant optimization to reduce annual costs and instill a sustaining culture of energy leadership!

24 7:30 a.m. Overall Goals and Objectives TASK 2 ENERGY AUDIT IDENTIFY POTENTIAL ECMS Proposed Audit Schedule Capital Region Water - Advanced Wastewater Treatment Facility Week of 7/10/2017 Monday, 7/10/2017 Tuesday, 7/11/2017 Wednesday, 7/12/2017 Thursday, 7/13/2017 Friday, 7/14/2017 8:00 a.m. Meeting with Senior Leadership Tanya Dierolf / Dave Stewart / Jess Rosentel Meeting to discuss the plan for the week, expectations, and confirm staff meetings Interview with first shift plant operators 9:00 a.m. Meeting with Plant Leadership 10:00 a.m. Tanya / Dave / Jess / Plant Supervisors 1. Review Plan with Plant Supervisors to coodinate interviews and identify key staff. 2. Review preliminary findings / understandings from Task Solicit input on energy opportunities or potential inefficiencies in energy consumption or process performance. Interview with maintenance supervisor Interview with field operations staff Pump Staff Site visits Facility Assessments and Analysis Final Meeting at AWTF with Senior Leadership and Plant Supervisors to walk through list of ECMs / projected improvements / estimated costs / etc 11:00 a.m. Capture and review information from interviews Plant Walk Through with Operations Staff 12 noon Lunch Break Lunch Break No. Energy/Water Conservation Method 2:00 p.m. Lunch Break 1:00 p.m. Energy Conservation Measure list development 3:00 p.m. 1. Equipment review, cataloguing, and runtime evaluations 2. Energy assessment and Process Systems Reviews 3. Identify potential sub-metering locations ECM Rating (1 - move forward, 2 - evaluate whether to move forward, 3 - for information only) Process 1. Equipment review, cataloguing, and runtime evaluations Area 2. Energy assessment and Process Systems Reviews 3. Re-assess based on supervisors input. Est. Annual Energy Savings (KWH). Very Rough Annual Energy Cost Savings ($/yr) Approx. Capital Cost AACE Class 5+ Facility Assessments and Analysis Ground-truth concepts and ideas Re-evaluate ($) and perform additional site walks Review operational data Simple Payback Period (months or yrs) Can ECM be implemented immediately? What monitoring is required to determine ECM effectiveness? Rating 1 Items - Potential Operational or Maintenance risks or concerns? Rating No. 2 and 3 Items - Comments 4:00 p.m. 5:00 p.m.

25 Energy Conservation Method Advanced Wastewater Treatment Facility Est. Annual Energy Savings (KWH) Rough Annual Energy Cost Savings ($/yr) - Rounded Rough Capital Cost $$ AACE Class 5+ Estimated Simple Payback Period (months or yrs) Consider turning off one Pure Ox train, at least seasonally (nos. shown are based on 12-month period). 750,000 $31,000 $0 Immediate Evaluate swing zone optimization when aerators are turned on/off. No need to aerate when ammonia limits are being met upstream, mix only. 170,000 $7,000 $5,000 6 months Evaluate channel air reduction/optimization. Reduce airflow rate without compromising mixing or CO 2 /N 2 stripping requirements. Systems are cross connected. 860,000 $35,750 $1,000 1 month Evaluate raising the inlet level on the Settled Sewage PS during normal flows to reduce pumping head. 55,000 $2,500 $2, months

26 Energy Conservation Method Water Services Center Consider VFDs to control backwash supply rate, as opposed to use of throttling valves. CRW Staff Recommendation Consider automating filter backwash and initiate based on headloss or turbidity, as opposed to filter run time. This would reduce number of backwashes (supply water, number air scours, and amount of waste water generated, pumped and disposed of). Consider lengthening pumping duration to upper Reservoirs (pumping same volume of water, for longer period of time, at lower rate) to reduce head loss and horsepower consumption Note: there are no 'time of day' electric rate differentials. Consider modifying finished water pumping strategy - operate 1 pump instead of 2 pumps. Interconnect the two clearwells. This project also improve plant hydraulic and process performance. CRW Staff Recommendation Est. Annual Energy Savings (KWH) Rough Annual Energy Cost Savings ($/yr) - Rounded Rough Capital Cost $$ AACE Class 5+ Estimated Simple Payback Period (months or yrs) 7,700 $500 $7, years 19,000 $800 $0 Immediate 34,000 $1,500 $0 Immediate 690,000 $29,000 $150,000 5 Years

27 CASE STUDY: LOUISVILLE MSD MORRIS FORMAN WQTC

LOUISVILLE S ONE WATER INITIATIVE MSD & LWC to cooperatively consolidate and share resources Fleet, IT, HR, Procurement, Customer Service, & Energy Goal: Save

28 LOUISVILLE S ONE WATER INITIATIVE MSD & LWC to cooperatively consolidate and share resources Fleet, IT, HR, Procurement, Customer Service, & Energy Goal: Save $800,000 - $900,000/year in Energy MSD chose to evaluate both energy & water at largest treatment plant HDR was selected to provide: o Energy & Water Management Plan

29 MFWQTC WATER & ENERGY SNAPSHOT MFWQTC Average Annual Energy and Water Snapshot (Nov through Jun. 2015) Volume Treated via Secondary Processes 31,500 MG/yr Average Flow (w/ Bypass) 99.6 MGD Average Flow (w/o Bypass) 86.4 MGD Electrical Energy Usage 75,809,000 kwh/yr Energy Intensity (w/ Bypass) 2,164 kwh/mg Energy Intensity (w/o Bypass) 2,440 kwh/mg Electrical Energy Billings $4,676,000 $/yr Peak Demand Billings $721,600 $/yr Intermediate Demand Billings $485,700 $/yr Base Demand Billings $482,800 $/yr Cost of Electric (includes demand charges) $ $/kwh Natural Gas Usage 267,400 DTH/yr Natural Gas Billings $1,490,900 $/yr Cost of Natural Gas $ $/DTH Potable Water Usage 299 MG/yr Potable Water Billings $660,200 $/yr Cost of Potable Water $2,210 $/MG Total Utility Cost (Electric, Gas, Water) $6,827,100 $/yr Demand Charges 36% of Total Electrical Energy Cost

PLANT BACKGROUND Louisville s largest treatment facility (combined sewage) o o Ohio River Discharge Plant located below flood levels Capacity: o o o Dry Weather: 140 MGD Wet

30 PLANT BACKGROUND Louisville s largest treatment facility (combined sewage) o o Ohio River Discharge Plant located below flood levels Capacity: o o o Dry Weather: 140 MGD Wet Weather: 350 MGD Average Daily Flow: 100 MGD Accepts/treats bio-solids from 5 regional WQTCs Contains a permitted wet weather bypass o All flow receives primary treatment and disinfection

MFWQTC - WET STREAM PROCESSES Mechanical

31 MFWQTC - WET STREAM PROCESSES Mechanical Screening Aerated and Vortex Grit Removal Primary Settling Biofiltration (Bio-roughing Towers) High Purity Oxygen Generation System Channel Aeration Final Settling Chlorination/Dechlorination Final Effluent Pumping (High River Stage)

Drum Dryers Shakers/Crushers/Classifiers Pellet Storage

32 MFWQTC - SOLIDS STREAM PROCESSES Dissolved Air Flotation Tanks Anaerobic Digesters Dewatering Centrifuges Rotary Drum Dryers Shakers/Crushers/Classifiers Pellet Storage Silos Scrubbers/Regenerative Thermal Oxidizers (Odor Control)

33 MFWQTC ESTIMATED RATE SUMMARY USING DEMAND CHARGES

34 DEVELOPING A BASELINE: WHAT IS MORRIS FORMAN USING & WHERE? 20% 19% 17% % OF TOTAL PLANT ELECTRICAL LOAD 15% 10% 5% 0% 15% 13% 12% 8% 5% 4% 4% 2% 1% PROCESS AREA

35 TOP ECM RECOMMENDATIONS Reduce Speed on all Mixers on all Oxygen Batteries Decommission the Bio-Roughing Towers Sequence Grit Pumping Operations Provide Additional Biogas Storage in Anaerobic Digesters Implement Real-Time Usage Monitoring (Energy Dashboards)

36 POTENTIAL FOR SIGNIFICANT WATER & ENERGY SAVINGS We Got Here By Collaborating! Potential For Over 25% Cost Reduction in Total Energy & Water Identified at MFWQTC

37 QUESTIONS AND COMMENTS

Energy Savings Plan Scope of Work Task 1: Baseline Analysis and Benchmark Data Development Task 2: Comprehensive Energy Audit and Assessment Task 3: Evaluation of Optimization Opportunities

39 Energy Savings Plan Scope of Work Task 1: Baseline Analysis and Benchmark Data Development Task 2: Comprehensive Energy Audit and Assessment Task 3: Evaluation of Optimization Opportunities Task 4: Evaluation of Alternative Energy Upgrades Task 5: Energy Procurement, Utility Rate, and Demand Response Evaluation Task 6: Report and Recommendations for an Energy Management Program

40 NOW WHAT?

Leveraging Energy Audits to Effect Cultural Changes and Long-Term Energy Savings

Leveraging Energy Audits to Effect Cultural Changes and Long-Term Energy Savings Rich Atoulikian, PMP, P.E. Kim Kennedy, P.E. OWEA 2012 June 2012 Outline Background Energy Consumption/Savings Opportunities