AWWA 20691-2016 Energy Management for Water Utilities.pdf

1、Energy Management fo r W ater U tili ti es Laura Dufresne, Editor Lee Ferrell, Technical EditorEnergy Management for Water Utilities Copyright 2016 American Water Works Association All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electron

2、ic or mechanical, including photocopy, recording, or any information or retrieval system, except in the form of brief excerpts or quotations for review purposes, without the written permission of the publisher. Disclaimer This book is provided for informational purposes only, with the understanding

3、that the pub- lisher, editors, and authors are not thereby engaged in rendering engineering or other profes- sional services. The authors, editors, and publisher make no claim as to the accuracy of the books contents, or their applicability to any particular circumstance. The editors, authors, and p

4、ublisher accept no liability to any person for the information or advice provided in this book or for loss or damages incurred by any person as a result of reliance on its contents. The reader is urged to consult with an appropriate licensed professional before taking any action or making any interp

5、retation that is within the realm of a licensed professional practice. AWWA Publications Manager: Gay Porter De Nileon AWWA Technical Editor/Project Manager: Melissa Valentine Project Coordinator: Kami Johle Butt AWWA Energy Policy Advisor: Adam Carpenter Cover Art: Melanie Yamamoto Production: Jani

6、ce Benight Library of Congress Cataloging-in-Publication Data Names: Dufresne, Laura, author. Title: Energy management for water utilities / by Laura Dufresne. Description: Denver, CO : American Water Works Association, 2015 | Includesbibliographical references. Identifiers: LCCN 2015050520 | ISBN 9

7、781625760630 Subjects: LCSH: Water utilities-Management. | Water utilities-Energyconservation. | Water utilities-Energy consumption. | Water-supplyengineering. Classification: LCC HD4456 .D84 2015 | DDC 363.6/10682-dc23 LC record available at http:/lccn.loc.gov/2015050520 Printed in the United State

8、s of America ISBN 978-1-62576-063-0 eISBN 978-1-61300-323-7 6666 W. Quincy Avenue Denver, CO 80235-3098 800.926.7337 www.awwa.orgiii Figures, vii Tables, ix Foreword, xi 1 Introduction 1 Purpose and Audience, 1 Energy Use By Water Utilities, 1 Benefits of Energy Management, 3 Energy Management Defin

9、itions, 4 A Balanced Approach, 5 How to Use This Handbook, 5 Other Resources, 6 References, 8 2 Energy Management Planning 11 Establish an Energy Team, 12 Develop Energy-Related Goals, 15 Develop the Utilitys Baseline, 15 Benchmark Energy Use, 18 Perform an Energy Audit, 19 Prioritize ECMs, 21 Simpl

10、e Payback, 22 Life-Cycle Costing, 23 Implement Improvements, 23 Evaluate Results and Communicate Successes, 24 References, 26 Contentsiv ENERGY MANAGEMENT FOR WATER UTILITIES 3 Management Measures 29 Energy Cost Savings Measures, 30 Energy Procurement Options, 30 Evaluating Energy Rate Structures an

11、d Fees, 32 Aligning Energy Use With Rate Structures, 34 System Operations Optimization, 38 System Operations Optimization Model, 39 Water Efficiency Measures, 42 Water Conservation Plans, 43 Supply-Side Management Measures, 43 Demand-Side Management Measures, 45 Asset Management, 47 Reducing Buildin

12、g Energy Use, 50 HVAC, 50 Lighting, 51 Building Energy Management Case Study, 53 References, 55 4 Technology Measures for Energy Efficiency 59 Motors, 59 Motor Efficiency, 60 Replacing Existing Motors With NEMA Premium Efficiency Motors, 62 Motor Control, 64 Matching Motors to Load, 64 Motor Managem

13、ent, 66 Optimizing Pumping System Energy Management, 67 Pumping Basics, 70 Pump Selection and Design, 74 Pump System Assessment, 81 Pumping System Improvements, 84 Water Treatment Equipment Modifications, 87 Conventional Treatment Processes, 88 Advanced Treatment Processes, 88 Examples of Energy Sav

14、ings, 92 References, 94Contents v 5 Renewable Energy . 97 Benefits of Renewable Energy, 100 Renewable Energy Applications, 101 Solar, 102 Wind, 104 Small to Microhydro, 106 Renewable Energy Cost Comparison, 108 Renewable Energy Procurement Strategies, 108 Own and Operate, 109 Power Purchase Agreemen

15、ts, 110 References, 110 6 Financing Alternatives . 113 Energy Utility Incentive and Rebate Programs, 114 Local, State, and Federal Energy Programs, 114 Drinking Water State Revolving Funds, 115 Energy Performance Contracting, 116 Leasing Options, 119 Online Resources, 120 References, 120 7 Conclusio

16、n .123 Appendix A Electric Energy Intensity per for Water Treatment Processes (in kWh/day) .125 Appendix B Life Cycle Cost Analysis (LCAA) Example 127 Index, 129Figure 1-1 Energy use for surface water system processes, 2 Figure 1-2 Typical energy breakdown for urban drinking water supply, 3 Figure 2

17、-1 Plan-Do-Check-Act management framework, 11 Figure 2-2 Possible energy leadership team structure, 14 Figure 2-3 ASHRAE standard audit types, 20 Figure 3-1 Water utility value chain, 30 Figure 3-2 Retail electricity markets, 2015, 31 Figure 3-3 Energy management opportunity: move water from source

18、to consumption area at lowest cost, 35 Figure 3-4 Shifting system pumping from peak to intermediate/off-peak periods, 37 Figure 3-5 System operations optimization model, 40 Figure 3-6 Advanced metering infrastructure systems (AMI), 44 Figure 3-7 Energy management evolution model, 48 Figure 3-8 Asset

19、 management model, 49 Figure 4-1 Sample lifetime motor operating costs, 60 Figure 4-2 Part-load efficiency (as a function of percent full-load efficiency), 62 Figure 4-3 Potential annual energy savings from NEMA premium motors, 63 Figure 4-4 Power triangle, 65 Figure 4-5 Example of motor nameplate,

20、66 Figure 4-6 Typical pump curve from a manufacturer, 71 Figure 4-7 Example of typical system curves, 73 Figure 4-8 Efficiency as a function of specific speed, 73 Figure 4-9 Drooping or rising head pump curve, 74 Figure 4-10 Flat head characteristics of a radial flow pump, 75 Figure 4-11 Flat head c

21、haracteristics of some mixed-flow pumps, 75 Figure 4-12 Continually rising head and peaking power characteristic pump curve, 76 Figure 4-13 Discontinuous pump curve characteristic, 77 Figure 4-14 Combined constant-speed and variable-speed pump at dangerously low speed, 80 vii Figuresviii ENERGY MANA

22、GEMENT FOR WATER UTILITIES Figure 4-15 Typical graph of system and pump curves, intersecting at the operating point, 83 Figure 4-16 System versus pump curves showing pump operating range, 83 Figure 4-17 Estimated electrical energy intensity (in kWh/day) for 10-mgd water supply and treatment processe

23、s, 89 Figure 5-1 US electricity production by source, 2014, 98 Figure 5-2 Wind resources map, 99 Figure 5-3 Typical solar photovoltaic system, 103 Figure 5-4 Wind turbine diagram, 105 Figure 6-1 Shared savings energy performance contracting (EPC) structure, 118 Figure 6-2 Guaranteed savings EPC stru

24、cture, 118Table 2-1 Energy conversion factors, 16 Table 2-2 Average intensity values for water utility processes, 18 Table 3-1 Shifting pumping to reduce demand and energy charges, 37 Table 3-2 Lighting upgrade optionstypical properties of light-source upgrade alternatives, 52 Table 4-1 Advantages a

25、nd disadvantages of constant-speed and variable-speed pumps, 79 Table 4-2 Energy-saving opportunities for conventional water treatment processes, 90 Table 4-3 Energy-saving opportunities for advanced water treatment processes, 91 Table 5-1 Estimated levelized cost of electricity (LCOE) for new power

26、 generation resources, 109 Table A-1 Electric energy intensity per for water treatment processes (in kWh/day), 125 ix Tablesxi Foreword AW WAs Energy Management for Water Utilities represents the most comprehensive and up-to-date reference on this important subject. This long-awaited publication is

27、coming out in the midst of one of the largest droughts in the history of Texas and California. How timely for the industry this book really is! What a great road- map for all of us to follow! AW WAs State of the Water Industry Report highlighted that “people are starting to see that water is more im

28、portant than oil.” How can water be more important than oil? How do we project the future of water and the importance of water efficiency? What future technologies will make water production more efficient, and how focused are water companies on really being efficient? Who really cares about the fut

29、ure of water? The greater focus on efficiency in the process of making clean drinking water available has been of increasing importance both to my company, Fairfax Water, and on a larger scale to the world in general. All companies large and small have a duty and obliga- tion to our customers to be

30、as efficient as possible while effectively using our re- sources wisely. The water/energy nexus is upon us. What we at Fairfax Water and what you as an energy professional in the water industry do to find new creative ways to keep costs down while efficiently providing clean water is vitally importa

31、nt. This book provides the necessary guidance and knowledge to better manage energy. The advancements of new lighting and energy efficient motors and products, which are better than ever, are now available at lower prices; and customers today are savvier and more energy focused. At Fairfax Water, we

32、 have had water efficiency as part of our strategic plan for many years, but early on we discovered that we needed a key performance indicator (KPI) that best measured our progress as a leader in the industry in water efficiency. The KPI at Fairfax Water that best measures our prog - ress is kWh/MG.

33、 Tracking this indicator is what is needed by water utilities world- wide such that the water resources can be managed efficiently to give our children and grandchildren clean water in the future. As a water professional and professional engineer with more than 25 years of experience in energy and e

34、ngineering, I am always impressed at the effort and enthusiasm that Fairfax Water employees, from the general manager to mechan- ics and electricians, bring to the job of making sure we are providing a first-class product to our customers. This entails keeping our key focus centered on improving xii

35、 ENERGY MANAGEMENT FOR WATER UTILITIES efficiency and keeping our customers costs as low as possible. Energy profession- als need to have all the tools to evaluate both supply-side and demand-side options. Energy Management for Water Utilities will give the reader the tools needed in an ever-changin

36、g energy world. At Fairfax Water and at many other leading US water companies, the approach for water efficiency and energy management must include strategically looking at each pump and installing energy technologies that increase efficiencies and lower costs. This comprehensive handbook presents m

37、any choices. I am pleased to have such a detailed energy book available. This handbook will help energy professionals in the water industry meet the new challenges ahead. As we look back on the energy arena, one thing becomes clear: People are start- ing to see that water is more important than oil!

38、 Shawn F. ONeill , P .E., CEM Manager, Energy Programs Fairfax Water Herndon, Virginia 1 1 Introduction Lee Ferrell (Schneider Electric), Angela Hintz (ARCADIS) PURPOSE AND AUDIENCE This handbook provides information about and insight into energy management strategies that can be used by water utili

39、ties to reduce operational costs, increase operational efficiencies, and develop more sustainable infrastructure. It is primarily for use by utility managers but also contains pertinent information for operators and other day-to-day personnel responsible for maintenance, engineering, and the perform

40、ance of water treatment and distribution systems. In addition, the material provided herein may be useful to consulting engineers and others who are inter- ested in design, operation, and sustainability of water systems. This handbook is specifically targeted at drinking water utilities; however, it

41、 contains information that may also be useful for wastewater utilities. ENERGY USE BY WATER UTILITIES According to recent research, the US municipal drinking water supply industry uses 39.2 terawatt hours per year (TWh/yr; 1 TWh = 1 million MWh) (EPRI Electric Power Research Institute and WRF Water

42、Research Foundation, also WaterRF) 2013). Water and wastewater services commonly may make up 30 to 40 percent of the total energy use in a municipality (USEPA 2014a). Many water treatment plants and distribution networks were constructed when energy costs were not a major factor. In current times, h

43、owever, energy costs can be a large por- tion (up to 35 percent) of the operational budget for water utilities, second only to staffing (Jacobs et al. 2003) Although energy is used for many water utility functions, the largest energy user by far is pumping. For surface water systems, EPRI and WRF (2

44、013) estimate that on average 86 percent of total energy demand is for raw-in-plant, and finished- water pumping (Figure 1-1). For groundwater systems, pumping is an even higher proportion because treatment energy costs are often negligible. Advanced treat- ment processes including membrane filtrati

45、on and desalinization might increase treatment energy use in the future, but EPRI and WRF note that 2 ENERGY MANAGEMENT FOR WATER UTILITIES Source: EPRI and WRF 2013 Figure 1-1 Energy use for surface water system processes in spite of anticipated upward trends in electrical energy use for the treatm

46、ent of drinking water, pumping continues to be the greatest elec- tricity end-use in water treatment systems and remains the principal focus of energy efficiency efforts. (EPRI and WRF 2013, p. 4-2) Figure 1-2 shows the average energy use at various steps of the municipal water cycle, from source th

47、rough treatment and distribution to the customers tap. The real energy use for a given water system, however, can vary widely. As reported by USEPA (2013), energy required for conveyance of raw water to the treatment plant ranges from 0 to 14,000 kWh/MG. Treatment and distribution require 100 16,000

48、 kWh/MG and 7001,200 kWh/MG, respectively. The range of energy requirements reflects the wide variety of source configurations (i.e., groundwater versus surface water, deep wells versus more shallow wells, distance to the treat- ment plant), treatment processes (chlorination only versus advanced tre

49、atment), topography, and layout of the customer connections (USEPA 2013). Energy use is predicted to rise in the future as a result of a number of factors. Dwindling sources of quality surface water and groundwater are driving utilities to use less desirable sources, which may require advanced treatment methods and dis- posal of additional waste products, such as brine and spent media. In addition, new regulations to protect public health often require advanced treatment processes that are more energy intensive than conventional treatment. For example, in response to