THERMAL ENERGY STORAGE:
From Power Poles to Politics
HELLO…
U.S. ELECTRIC GRID
NORTHEAST ISO - EXAMPLE LOAD PROFILE
Source: ISO New England, www.iso-ne.com
LEAST EFFICIENT
WIND FARM
ENERGY STORAGE CONCEPT

Energy is stored during “off-peak”
periods, then distributed during
“peak” periods of use.
• Examples of energy storage systems:

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The human body
Batteries
Hot water heaters
Commercial & industrial energy storage
systems
TYPES OF ENERGY STORAGE SYSTEMS

Traditional commercial-scale utility storage:
• Pumped Hydro (PH)

Developing storage technologies:
• Compressed Air Energy Storage (CAES)
• Electro-Chemical Batteries
• Flywheels
• Superconducting Magnetic ES (SMES)

Thermal Energy Storage (TES)
COMPARING STORAGE TECHNOLOGIES
Pumped Hydro – proven but costly,
inefficient, hard to site.
 CAES, Batteries, SMES, Flywheel – still in
the developmental phase, costly (however,
some may be suited to rapid discharge).
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Thermal Energy Storage (TES):
• Proven track record for over 30 years.
• Low cost and efficient
• Both demand side savings and now supply-
side
• Wide range of sizes of 1-100 MW.
COMMERCIAL / INDUSTRIAL TES SYSTEMS

Ice Storage
• Stores energy in an ice
phase.
• Relatively small
footprint, ideal for
urban applications

Stratified Chilled Water
• Stores energy in the
chilled water phase.
• Economical in larger
applications (>2,500
ton-hrs.)
BIG “re-chargeable batteries” for use each day
TES WITH DISTRICT COOLING SYSTEMS
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District cooling systems serve large commercial
and industrial facilities
TES enhances the value of district cooling by
providing daily dispatchable electrons
CHILLED WATER TES CONCEPT
CHILLED WATER TES CONCEPT
CHILLED WATER TES CONCEPT
SHIFTING THE COOLING LOAD
Permanent Demand Reduction
Load Profile without TES
Load Profile with TES
…and reduces energy consumption and air emissions at
the source.
TES ADDRESSES POWER CHALLENGES
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Peak Power Requirements will Increase
– TES lowers peak power for the grid
Additional Transmission – TES reduces
this requirement by allowing low usage
at night to increase, and daytime
power to decrease
Variable Electric Power Costs – TES
reduces the need for less efficient
peaker plants to operate.
Increasing Intermittent Renewable
Power – TES enables renewable power
sources to be utilized more effectively.
CHILLED WATER TES APPLICATIONS
College Campuses
Government & Municipalities
Private Industry & Data Centers
NG Electric Power Plants
CHILLED WATER TES PROJECTS
Supply-side TES Example
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Application: Turbine Inlet Cooling (TIC)
Location: Jacksboro, TX - NG Power Plant
Initial Operation: 2008
Demand-side TES Example
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Application: District Cooling
Location: Orlando, FL – College Campus
Initial Operation: 2009
GAS TURBINE POWER PLANT PERFORMANCE
Performance
goes down as
outside air temp
goes up
TURBINE INLET COOLING FOR NG POWER PLANT
Combustion Turbine
TES Tank
Ambient Air
Chilled Water
Cooling Coil
Chiller Plant
Turbine inlet cooling improves NG power
plant performance.
JACKSBORO, TX – NG POWER PLANT

Scope of Work:
• New 6.0 MG TES tank
• New 14,524-ton modular CHW
plant & cooling coils by TAS

Project Performance:
• Reduced inlet combustion air
temp to 50°F on a peak day
• Increased power generation
capacity by a net 110.2 MW
NG Electric Power Plant w/ TES Tank
ORLANDO, FL – UNIVERSITY OF CENTRAL FLORIDA

Project Objectives:
• Increase chilled water
cooling capacity to keep
pace with enrollment
• Minimize energy costs
associated with cooling
• Take advantage of utility
company incentives for offpeak energy use
ORLANDO, FL – UNIVERSITY OF CENTRAL FLORIDA

Scope of Work:
• New 3.0 MG TES Tank
• New CHW pumps, piping
and controls
• Chilled water control
strategy that takes
advantage of off-peak
electric rates
ORLANDO, FL – UNIVERSITY OF CENTRAL FLORIDA
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Project Performance:
• Energy cost savings of
over $700,000 annually
• Rebate from the utility
company of $637,000
• Owner quote: “… our only
regret is that we didn’t
build a bigger tank.”
RENEWABLE ENERGY AND STORAGE
The value of storage continues to grow as:
• HVAC loads drive demand, widening the gap
between peak and base load demand
• Time-of-day differentials grow in marginal heat
rates, emissions, and value of electricity
• Intermittent power generation from renewable
energy sources grows, but is sometimes out of
phase with electric demand
Practical, economical energy storage can play a
key role in electric power systems.
• The November 2007 California ISO report
“Integration of Renewable Resources”
CONGRESS MAY ACT TO INCENTIVIZE STORAGE
Storage Bills are in
committee review, and for
consideration for a
approval as early as 2010.
 Passage of these bills
could result in 20-30%
incentive for new TES

Senate Bill
House Bill
BENEFITS OF THERMAL ENERGY STORAGE
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Reduces Demand Side energy costs:
• Reduces peak electric demand – 10 to 40%
• Saves energy – 5 to 15% for chilled water TES
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Reduces Supply Side energy usage at power plant from 5% to
30% depending on the location and generating equipment.
Reduces emissions at the power generation source.
Reduces capital costs for expansion including:
• Displacing chiller plant equipment
• Reducing the need for more power generation & transmission lines
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Provides an additional level of cooling redundancy.
Enables a greater amount of use of renewable intermittent
sources of energy (such as wind)
Guy Frankenfield. P.E.
Office (972) 823-3300
Mobile (214) 755-4610
Email gfrankenfield@natgun.com