Thermal storage, such as ice-making air conditioners, can help save the electric grid by shifting demand from peak daytime hours to overnight. As climate change increases demand for air conditioning, renewable sources like wind are intermittent and don't always match peak demand. Thermal storage allows excess wind power generated at night to be stored as ice and used to power air conditioning during the day, reducing strain on the grid. Many commercial buildings already use such systems successfully to lower costs and emissions. Widespread adoption of thermal storage could help integrate more renewable energy and avoid the need for new power plants.

1. How Thermal
Storage Can
Save the Grid
Modified from a Presentation at
Green California Summit
Elton Sherwin
Managing Director, Ridgewood Capital

2. Warmer Future
Number of Days Over 100ºF
Recent Past, 1961-1979 Higher Emissions Scenario, 2080-2099
White House Report on Climate Change
2

3. More Demand for Air Conditioning
2009 California Climate Adaptation Strategy
Source: www.climatechange.ca.gov/adaptation

4. Renewable Power Will Save Us?
But there are some problems…

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 wind
Chart modified from Cal ISO,
2007 Summer Loads and Resources Operations Assessment
http://www.caiso.com/1b95/1b95abb649df4.pdf

6. The More Wind You Use,
The More Storage You Need

7. Even the Sun is Intermittent

8. Let’s look at the problem
a bit differently
What is driving all the
demand?

9. Air Conditioning
California
Electricity
Usage
A/C
Summer
Source: California Energy Commission

10. To Use Renewables,
We Must Control the Air Conditioning
Air Conditioning
Hot Water
Pools
Everything Else
Florida August Electricity Hour of Day
Source: Florida Solar Energy Center

11. Need A Lot of Storage to Use
Wind to Power Summer Air Conditioning
Air Conditioning
Hot Water
Pools
Everything Else
Hour of Day
Source: Florida Solar Energy Center

12. Thermal Storage
• Big Three
– Baltimore Air Coil
– CALMAC
– Ice Energy
• Many Independents
– Hill York in South Florida
– Others
Baltimore Air’s Ice Chiller Ice Energy’s Ice Bear Calmac’s Ice Bank

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. Many Case Studies…
Taipei 101
Baltimore Air Coil project

15. Savings Are Significant
Source: CALMAC case study

16. Benefits
For 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. Benefits
Benefits 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. Cost of Thermal Storage
Customer Pays:
• New commercial
– Free
– Fewer tons of AC pay for “ice chests”
• Commercial retrofits
– 2 to 5 years B/E w/o subsidies
Utility Pays:
• Cheaper than peaker plant

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. Thermal Storage in Refrigerators
• Good sources of information:
– Dynamic Demand, a UK non-profit
focused on autonomous demand control
www.dynamicdemand.co.uk
– Pacific Northwest Lab: GridFirendly
Appliance Project
• Startup to watch: RLtec in the UK.
(www.rltec.com)

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
(www.sequentric.com)

22. Move and Change the Type of Demand

23. Recommendations
From 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. Conclusions
Thinking about renewable
Think about thermal storage
It is hard to get cheaper than water

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 www.EltonSherwin.com
Library of Congress Control Number: 2010929887
ISBN-10: 0-9827961-0-2
ISBN-13: 978-0-9827961-0-8
Energy House Publishing
www.EnergyHousePublishing.com

26. Smart Grid Critical Success Factor
Require 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 with
should have thermal storage units and be
“Nighttime” Air Conditioners
capable of running at night. Over 2,000
“nighttime air conditioners” have been in- General Electric Co. Cincinnati
stalled in America and the evidence is very U.S. Court House S. Boston
clear. They: BP Plaza Houston
Qualcomm San Diego
x Emit less CO2.242 Doubletree Hotel San Diego
Army National Guard Manassas
x Avoid the need for new coal plants.
Heritage Museum Center Cincinnati
x Save money for building owners.243 Indiana State University Terre Haute
Inter-Island Terminal Honolulu
x Use intermittent wind power.244 Children’s Hospital Birmingham
Dozens of studies verify that these Bellevue Place Bellevue
systems pay for themselves. Yet less than The Trane Company LaCrosse
1% of America’s six million commercial First Interstate Bank Milwaukee
buildings have installed these thermal stor- Carolina Medical Center Charlotte
Kaiser Hospital San Diego
age units that enable air conditioners to
C.U.N.Y. Brooklyn
run 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. Key to solving America’s
energy problem is reducing
demand for
air conditioning,246
then
shifting consumption into
the night,
storing energy as ice,
and
enabling air conditioners to
use intermittent
wind power.
A VENTURE CAPITALIST’S PERSPECTIVE 177

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 hot
afternoons is reduced by over 90%, and it takes less electricity to make the ice at night
because the outside air is cooler.
Credit Suisse moved its air-conditioning load from the day shift to the night shift
on its building in New York. On just this one building, Credit Suisse saves 2.15 million
kWh every year.101 Commercial building owners regularly report saving over $50,000 a
year in electricity.102
Thousands of thermal storage systems are installed across America. From
Boston 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 in
Alaska.
78 ADDICTED TO ENERGY

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, electricity
demand is highest in the afternoon and lowest at night. Move air-conditioning load into
the middle of the night, and power is freed up on hot summer afternoons, which is
usually 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 move
air-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 off
several times during the night with no effect on the building, the ice unneeded until the
next day. This makes nighttime air conditioners ideal users of wind power. In the event
of an unexpected drop in wind speed, a utility has several hours to find an alternate
source 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. 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’s
intermittent nighttime power. Wind energy can be produced at night, stored as ice, and
then 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 the
grid on hot afternoons, when the grid is congested. This load shifting—from daytime
power 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 dollars
upgrading the electric grid, but less expensive.103
Nighttime air conditioners make sense anywhere there is predictable demand for
air conditioning. They are effective in homes and businesses, in any building needing
three or more months of annual air conditioning. A company called Ice Energy makes a
system similar to the one used by Credit Suisse, but much smaller and more affordable
for large homes and small commercial buildings. Calmac and Baltimore Air Coil make
systems for larger commercial buildings.*
The 100-Day Rule
Predictable air conditioning loads exist across America. Many states have
buildings using air conditioners over 100 days a year. Homes and businesses in Southern
states use a lot of air conditioning. Surprisingly, many commercial buildings in the North
run their air conditioners over 100 days per year, even on cool days.
All new air conditioners—commercial and large residential—used over 100 days
a 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 bank
systems.’ Or see www.ice-energy.com, www.baltimoreaircoil.com and www.calmac.com.
80 ADDICTED TO ENERGY

31. Acknowledgements
Many people shared their time and insights in the creation of this book. I would
like to specially thank those who provided encouragement, advice, and assistance: Jim
Sweeney, 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, Nicholas
Parker, 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 to
thank: Stanford University, Department of Global Ecology—Carnegie Institution for
Science, Precourt Energy Efficiency Center, Woods Institute for the Environment, Earth
Policy Institute, Lawrence Berkeley National Laboratory, Intergovernmental Panel on
Climate Change, U.S. Department of Energy, National Academy of Sciences, U.S.
Environmental Protection Agency, California Energy Commission, California Air
Resources Board, Natural Resources Defense Council, Environmental Defense Fund,
Berkeley Energy and Resources Collaborative, TUC radio, NASA, European Space
Agency, National Center for Atmospheric Research, National Renewable Energy
Laboratory, Energy Information Administration, Woods Hole Research Center, Pacific
Gas and Electric, Global Climate and Energy Project at Stanford University, Cleantech
Group, 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 been
especially influenced by the writings, lectures and speeches of Nicholas Stern, Stephen
Schneider, Ken Caldeira, Chris Field, James Hansen, Lester Brown, Fred Krupp, Amory
Lovins, 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 a
project 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. Elton Sherwin is a venture capitalist and the Senior Managing
Director at Ridgewood Capital, where he invests in private companies.
He holds eight patents and sits on the boards of several cleantech
companies.
His widely acclaimed first book, The Silicon Valley Way, was
translated into Chinese, Japanese, Spanish, and Korean. First published in
1998, it continues to be read and used by entrepreneurs and universities
around the world. He frequently speaks at conferences and guest lectures
at Stanford University.
Mr. Sherwin earned his B.A. in Political Science from the
University of California at Berkeley. The author worked for two decades
at IBM and Motorola, where his products earned numerous awards.
330 ADDICTED TO ENERGY

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 because
of 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. “I couldn't put it down. It's 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 don't 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