How Thermal Storage Can Save the Grid


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How Thermal Storage Can Save the Grid

  1. 1. How Thermal Storage Can Save the Grid Modified from a Presentation at Green California Summit Elton SherwinManaging Director, Ridgewood Capital
  2. 2. Warmer Future Number of Days Over 100ºF Recent Past, 1961-1979 Higher Emissions Scenario, 2080-2099White House Report on Climate Change 2
  3. 3. More Demand for Air Conditioning 2009 California Climate Adaptation StrategySource:
  4. 4. Renewable Power Will Save Us? But there are some problems…
  5. 5. Wind is Intermittent Peak Wind 10 pm to 1 am Peak summer demand for electricity is at 4 to 6 pm, over 16 hours after peak windChart modified from Cal ISO,2007 Summer Loads and Resources Operations Assessment
  6. 6. The More Wind You Use,The More Storage You Need
  7. 7. Even the Sun is Intermittent
  8. 8. Let’s look at the problem a bit differentlyWhat is driving all the demand?
  9. 9. Air Conditioning California Electricity Usage A/C SummerSource: California Energy Commission
  10. 10. To Use Renewables,We Must Control the Air Conditioning Air Conditioning Hot Water Pools Everything Else Florida August Electricity Hour of DaySource: Florida Solar Energy Center
  11. 11. Need A Lot of Storage to UseWind to Power Summer Air Conditioning Air Conditioning Hot Water Pools Everything Else Hour of DaySource: Florida Solar Energy Center
  12. 12. Thermal Storage• Big Three – Baltimore Air Coil – CALMAC – Ice Energy• Many Independents – Hill York in South Florida – OthersBaltimore Air’s Ice Chiller Ice Energy’s Ice Bear Calmac’s Ice Bank
  13. 13. Make Ice at Night• Air conditioner runs at night• Making ice at night• Wind energy is stored as ice• Little or no change in ductwork• Daytime load reduced by over 50%
  14. 14. Many Case Studies… Taipei 101 Baltimore Air Coil project
  15. 15. Savings Are SignificantSource: CALMAC case study
  16. 16. BenefitsFor the Rate Payer:• Off-peak rates• Reduced demand charges• Better comfort• LEED credit• Keep facility open during power emergency or outage Merchandise Mart in Chicago CALMAC Systems Baltimore Air Coil System
  17. 17. BenefitsBenefits to Utility:• Tolerant of intermittent power• Uses off-peak power• Avoid CAPX – Plant – Transmission• Improves grid reliability• Probably improves grid efficiency & reduces CO2 +• “Free” / pays for itself always – According to vendors
  18. 18. Cost of Thermal StorageCustomer Pays:• New commercial – Free – Fewer tons of AC pay for “ice chests”• Commercial retrofits – 2 to 5 years B/E w/o subsidiesUtility Pays:• Cheaper than peaker plant
  19. 19. Thermal Storage: UK Fridge Experiment• Refrigerator monitors power quality• Backs off when the wind dies• Turns on early in times of excess wind• Based solely on power quality, no signal• Equivalent of GW of demand management at the edge
  20. 20. Thermal Storage in Refrigerators• Good sources of information: – Dynamic Demand, a UK non-profit focused on autonomous demand control – Pacific Northwest Lab: GridFirendly Appliance Project• Startup to watch: RLtec in the UK. (
  21. 21. Thermal Storage: Water Heaters• Least expensive to retrofit• Almost 40% (41 million out of 107 million) of US domestic households’ hot water are electric – Similar benefits to ice storage• More than turning off water heaters – Schedule the load • Match availability of wind – Automatic under frequency load shedding – Cold load pickup wait for “OK to turn on”• Startup to watch: Sequentric Energy Systems (
  22. 22. Move and Change the Type of Demand
  23. 23. RecommendationsFrom my book:• Thermal storage be required – All new compressors and cooling towers • New and retrofit commercial • Over 90 days a year of use.• Require radios on all grid-connected AC systems – For power emergencies• Intermittent power on the rate table – Different from of time-of-use rates• Thermal storage is ideal candidate for on-bill financing (OBF)• Require refrigeration equipment be on DR
  24. 24. Conclusions Thinking about renewable Think about thermal storage It is hard to get cheaper than water
  25. 25. Excerpts from Addicted to Energy A Venture Capitalist’s Perspective on How to Save Our Economy and Our Climate Elton B. Sherwin, Jr. Copyright 2010 Elton Sherwin These pages may reprinted with attribution: From Addicted to Energy Copyright 2010 Elton Sherwin For more information, as well as downloads of the author’s PowerPoint presentations, please visit Library of Congress Control Number: 2010929887 ISBN-10: 0-9827961-0-2 ISBN-13: 978-0-9827961-0-8 Energy House Publishing
  26. 26. Smart Grid Critical Success FactorRequire Commercial Air Conditioners to Run at Night Credit Suisse moved its air-conditioning load from the day shift to the night shift on one building in New York. This reduced CO2 emissions by 3.6 million pounds per year.240 Every commercial air conditioner Buildings withshould have thermal storage units and be “Nighttime” Air Conditionerscapable of running at night. Over 2,000“nighttime air conditioners” have been in- General Electric Co. Cincinnatistalled in America and the evidence is very U.S. Court House S. Bostonclear. They: BP Plaza Houston Qualcomm San Diegox Emit less CO2.242 Doubletree Hotel San Diego Army National Guard Manassasx Avoid the need for new coal plants. Heritage Museum Center Cincinnatix Save money for building owners.243 Indiana State University Terre Haute Inter-Island Terminal Honolulux Use intermittent wind power.244 Children’s Hospital Birmingham Dozens of studies verify that these Bellevue Place Bellevuesystems pay for themselves. Yet less than The Trane Company LaCrosse1% of America’s six million commercial First Interstate Bank Milwaukeebuildings have installed these thermal stor- Carolina Medical Center Charlotte Kaiser Hospital San Diegoage units that enable air conditioners to C.U.N.Y. Brooklynrun at night. American River College Sacramento Pasadena City College Pasadena Northern cities are in bold Source: Calmac Manufacturing Corp241 The world’s tallest building, Taipei 101, has an ice storage system installed from the Baltimore Air Coil Company.245 It is time to upgrade all six million commercial buildings in America. Give building owners 10 years to convert, and then pull the plug on any air conditioners that do not have thermal storage. It will save the building owners money, create jobs in America, and enable America to exploit its vast wind resources. 176 ADDICTED TO ENERGY
  27. 27. Key to solving America’senergy problem is reducing demand for air conditioning,246 then shifting consumption into the night, storing energy as ice, andenabling air conditioners to use intermittent wind power. A VENTURE CAPITALIST’S PERSPECTIVE 177
  28. 28. 22. Ban the Installation of Large Daytime Air Conditioners Large air conditioners should be run at night.Nighttime Air Conditioning Is a Big Story, Not Well Understood Nighttime air conditioners make ice or ice slurry at night that is stored in a“thermal storage unit,” a large ice chest. During the day, the ice slurry cools the building,using the existing ductwork, pipes, and fans. Electricity consumption during hotafternoons is reduced by over 90%, and it takes less electricity to make the ice at nightbecause the outside air is cooler. Credit Suisse moved its air-conditioning load from the day shift to the night shifton its building in New York. On just this one building, Credit Suisse saves 2.15 millionkWh every year.101 Commercial building owners regularly report saving over $50,000 ayear in electricity.102 Thousands of thermal storage systems are installed across America. FromBoston to Seattle, Miami to San Diego, Chicago to Houston, these systems work any-where there is a large summer air-conditioning load. At least one system is installed inAlaska. 78 ADDICTED TO ENERGY
  29. 29. Switching air conditioning into the night will enable your state to use large amounts of wind power.Advantages of Thermal Storage Units Nighttime air conditioners provide the same comfort as existing air conditioners,and they have several big advantages for your state: Avoid the need for new power plants. As the previous chart shows, electricitydemand is highest in the afternoon and lowest at night. Move air-conditioning load intothe middle of the night, and power is freed up on hot summer afternoons, which isusually the driver forcing construction of new power plants and new transmission lines. Use cheaper power. Power between midnight and 4 a.m. is much cheaper.Demand is low and there is surplus capacity. Use intermittent wind power. This may be the most important reason to moveair-conditioning demand from the day shift to the night shift. Today’s air conditioners must be powered the instant they are turned on.Nighttime air conditioners can be managed by the electric utility, turned on and offseveral times during the night with no effect on the building, the ice unneeded until thenext day. This makes nighttime air conditioners ideal users of wind power. In the eventof an unexpected drop in wind speed, a utility has several hours to find an alternatesource of power, something easily done at night but nearly impossible on a hot after-noon. Since the grid is lightly loaded at night, wind power can be sent long distances, something impossible on hot afternoons. A VENTURE CAPITALIST’S PERSPECTIVE 79
  30. 30. Nighttime air conditioners are the long-sought-after way to store the wind’s intermittent power. Wind power is stored in ice.Wind Power and Nighttime Air Conditioners Nighttime air conditioners are the long-sought-after way to store wind’sintermittent nighttime power. Wind energy can be produced at night, stored as ice, andthen used during the day. Since the grid is lightly loaded at night, wind power can be sent long distances,something impossible on hot afternoons when the grid is stretched to its limit. Switching air conditioning into the night removes enormous demand from thegrid on hot afternoons, when the grid is congested. This load shifting—from daytimepower to nighttime power—protects the grid by removing demand from hot afternoons,when it is most vulnerable to outages. This is equivalent to spending billions of dollarsupgrading the electric grid, but less expensive.103 Nighttime air conditioners make sense anywhere there is predictable demand forair conditioning. They are effective in homes and businesses, in any building needingthree or more months of annual air conditioning. A company called Ice Energy makes asystem similar to the one used by Credit Suisse, but much smaller and more affordablefor large homes and small commercial buildings. Calmac and Baltimore Air Coil makesystems for larger commercial buildings.*The 100-Day Rule Predictable air conditioning loads exist across America. Many states havebuildings using air conditioners over 100 days a year. Homes and businesses in Southernstates use a lot of air conditioning. Surprisingly, many commercial buildings in the Northrun their air conditioners over 100 days per year, even on cool days. All new air conditioners—commercial and large residential—used over 100 daysa year should be nighttime units. Most new air conditioners should run at night. * For more information, Google ‘night ice air condition,’ ‘ice bear ppt,’ and ‘CALMAC ice banksystems.’ Or see, and 80 ADDICTED TO ENERGY
  31. 31. Acknowledgements Many people shared their time and insights in the creation of this book. I wouldlike to specially thank those who provided encouragement, advice, and assistance: JimSweeney, Marion O’Leary, Carole and Dale Grace, Warren Muir, Ed Beardsworth,Susan Arrington, John Monti, Bob Gold, Davis Masten, Lynn Pieron, Arthur Rypinski,Amanda Rubio, David Andresen, Meritt Sawyer, Bob Barrett, Carol Smith, NicholasParker, Allan Aaron, Daniel Carter, Bob Lafferty, Philip Kithil, Julie Clugage, Abe Sofaer,Jagan Nemani, Jon Brodeur, Jon Foster, James O’Brien, John Mashey, Jonathan Livingston,Carroll Harrington, Bill Keating, Dave Goerz, Shelley Sousa and David Cheng. I have drawn on the work and research of many organizations and would like tothank: Stanford University, Department of Global Ecology—Carnegie Institution forScience, Precourt Energy Efficiency Center, Woods Institute for the Environment, EarthPolicy Institute, Lawrence Berkeley National Laboratory, Intergovernmental Panel onClimate Change, U.S. Department of Energy, National Academy of Sciences, U.S.Environmental Protection Agency, California Energy Commission, California AirResources Board, Natural Resources Defense Council, Environmental Defense Fund,Berkeley Energy and Resources Collaborative, TUC radio, NASA, European SpaceAgency, National Center for Atmospheric Research, National Renewable EnergyLaboratory, Energy Information Administration, Woods Hole Research Center, PacificGas and Electric, Global Climate and Energy Project at Stanford University, CleantechGroup, Scripps Institution of Oceanography, CalCars, Union of Concerned Scientists,Food and Agriculture Organization of the United Nations, Palo Alto University Rotary,Mineral Acquisition Partners, and Ridgewood Capital. My thoughts on the topic of climate change and energy policy have beenespecially influenced by the writings, lectures and speeches of Nicholas Stern, StephenSchneider, Ken Caldeira, Chris Field, James Hansen, Lester Brown, Fred Krupp, AmoryLovins, Al Gore, Thomas Friedman, Thomas Wenzel, Marc Porat, Richard Wolfson,Stacy Jackson, Arnold Schwarzenegger, David Paterson, Jeffrey Sachs, Dianne Feinstein,Bill Gates, Ted Turner, Robert Swanson, and Fred Pearce. I would like to thank my daughters, who have provided encouragement for aproject that has lasted many years and has stolen thousands of hours from our family.And, most of all, I thank my wife, without whom this book would never have happened.The views expressed are those of the author and do not necessarily represent the views of the individuals or organizations quoted or cited. A VENTURE CAPITALIST’S PERSPECTIVE 329
  32. 32. Elton Sherwin is a venture capitalist and the Senior ManagingDirector at Ridgewood Capital, where he invests in private companies.He holds eight patents and sits on the boards of several cleantechcompanies. His widely acclaimed first book, The Silicon Valley Way, wastranslated into Chinese, Japanese, Spanish, and Korean. First published in1998, it continues to be read and used by entrepreneurs and universitiesaround the world. He frequently speaks at conferences and guest lecturesat Stanford University. Mr. Sherwin earned his B.A. in Political Science from theUniversity of California at Berkeley. The author worked for two decadesat IBM and Motorola, where his products earned numerous awards. 330 ADDICTED TO ENERGY
  33. 33. Praise for Addicted to Energy “Insightful” Vinod Khosla Khosla Ventures“A creative approach to solving our energy problems that demonstrates the power the private sector can bring to bear on global issues.” Michael G. Morris Chairman, President and Chief Executive Officer American Electric Power Co. “Sherwin proposes many straightforward yet innovative policies to deploy technology already developed, but languishing, unused.” Steve Jurvetson Managing Director, Draper Fisher Jurvetson “Elton Sherwin’s letter to a fictional governor is in fact a letter to all of us.Sherwin offers a detailed overview of the very real dangers to our planet becauseof practices that are within our human power to abandon or control. None of us can do it all, but this book points us to realistic steps we each can take in the direction of a more effective and faithful environmental stewardship.” Richard J. Mouw President, Fuller Seminary
  34. 34. “I couldnt put it down. Its smart, practical, and proves the point that what is good for the environment is good for the economy.” David Miller Mayor of Toronto “Simple solutions for governments, corporations, and individuals” William F. Miller Former Provost of Stanford University "Sherwin lays out an action plan tackling the most economically and environmentally attractive options we have. You dont need to agree with everything he says to find enough good ideas to fill the agenda for any state, county, city, or family." James Sweeney Director, Precourt Energy Efficiency Center, Stanford University “A practical cookbook for consumers, industrialists and policy makers. …Bravo!” Bill Keating Executive Chairman, Skyline Solar “A magnificent roadmap for creating jobs, wealth and real progress” Nicholas Parker Executive Chairman, Cleantech Group