Application of a Small-Scale

8/11/2019 Application of a Small-Scale

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American Public Power AssociationDemonstration of Energy-Effic ient Developments (DEED)

Application of a Small Scale

Thermal Energy Storage System

Final Report

Prepared by:

City of AnaheimPublic Utili ties Department201 S. Anaheim B lvd., Suite 801

Anaheim, CA 92805


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July 2005


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ABSTRACT

The City of Anaheim Public Utilities Department conducted a research anddemonstration test of a small-scale Thermal Energy Storage (TES) system at aCity fire station in 2004-05. TES systems have previously targeted installations in

larger commercial buildings that have a significant cooling load. Small-scale TESrepresents a breakthrough in technology, manufacturing and packaging thattargets the smaller 5 to 10-ton air conditioning systems that are prevalent in smallcommercial facilities in Anaheim.

The demonstration was successfully deployed and ran for nine months. Data wascollected to evaluate the impacts to the facility and to the utility. Anaheim hasrecommended that other member agencies in the Southern California PublicPower Authority (SCPPA) conduct trials to gather more field experience indifferent applications, and to jointly develop customer offerings such as time-of-use (TOU) rates and incentives to help offset initial costs of the system.


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TABLE OF CONTENTS

ABSTRACT......................................................................................... I

TABLE OF CONTENTS..................................................................... II

LIST OF FIGURES............................................................................IV

LIST OF TABLES ..............................................................................V

1.0 INTRODUCTION....................................................................... 1

1.1

Background ............................................................................. 1

1.2 Project Object ives ................................................................... 1

1.3 TES Theory of Operation ........................................................ 2

1.4 Uti li ty Perspective ................................................................... 3

2.0 PROJECT METHODOLOGY.................................................... 4

2.1

TES System Descr iption ......................................................... 4

2.2

Site Descript ion ....................................................................... 8

2.2.1

Site Characterist ics...........................................................................8

2.2.2 Facili ty Energy Profi le ....................................................................10

2.2.3 Site Requirements...........................................................................12

2.2.4 System Design ................................................................................13

2.3

Project Implementation ........................................................ 15

2.3.1

Approval Process ............................................................................15

2.3.2

Construction....................................................................................17

3.0 RESULTS ............................................................................... 23

3.1

Unit Data Analysis................................................................. 23


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3.2

Facili ty Data Analysis ........................................................... 25

3.3

Comfort and Availabili ty ....................................................... 27

4.0

FUTURE PLANS AND APPLICABILITY................................ 27

5.0 SCHEDULE ............................................................................ 29

6.0 BUDGET................................................................................. 30

7.0 CONCLUSIONS...................................................................... 31

APPENDIX A. ICE BEAR PRODUCT BRIEF.................................... 1


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LIST OF FIGURES

Figure 1. Demand Profile of a Facility Before (top) and After (bottom)Implementation of TES ..................................................................................2

Figure 2. Ice Bear 50 TES System (courtesy of Ice Energy, LLC).....................4

Figure 3. Ice Bear Unit (right) and Standard Condensing Unit (left)......................5

Figure 4. Anaheim Fire Station .............................................................................8

Figure 5. Fire Station Site Layout..........................................................................9

Figure 6. Mechanical Equipment Well with Existing Air Conditioning Units ........10

Figure 7. Fire Station Daily Usage and Load Factor (by billing period)...............11

Figure 8. Facility Energy Profile for Peak Day (Sept. 5, 2004)............................11

Figure 9. Fire Station Walkway Area (front view from street)..............................12

Figure 10. Fire Station Walkway Area (rear view)...............................................13

Figure 11. TES System Block Diagram...............................................................14

Figure 12. TES Installation Diagram ...................................................................15

Figure 13. Anaheim Approval Process Flow Chart .............................................16

Figure 14. Site Clearing ......................................................................................18

Figure 15. Placement of TES and Condensing Unit onto Concrete Pad.............18

Figure 16. Installation of New Evaporator Coil ....................................................19

Figure 17. Refrigerant Lines on Facility Rooftop.................................................19

Figure 18. Refrigerant Lines Along Wall, and Condenser Electric Disconnect....20

Figure 19. Aluminum Tape Wrapped Around Refrigerant Line Insulation...........21

Figure 20. Ice Forming on Coils Inside Ice Bear Unit ..........................................21

Figure 21. Two-Stage Thermostat ......................................................................22

Figure 22. Completed Installation .......................................................................22

Figure 23. Demand Profile Prior to Ice Bear Installation (Roof Top Unit)............23

Figure 24. Demand Profile After Ice Bear Installation .........................................24

Figure 25. Combined Demand Profile (Ice Bear and Existing Air Conditioner) ...25

Figure 26. Energy Shifted versus Ambient Temperature .....Error! Bookmark notdefined.

Figure 27. Facility Billing Meter Before and After TES Installation...................26


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LIST OF TABLES

Table 1. Ice Bear 50 Product Data ....................................................................5

Table 2. Daily Energy Totals...............................................................................25

Table 3. Facility Billing Summary Comparison....................................................26

Table 4. Project Schedule...................................................................................29


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1.0 INTRODUCTION

1.1 Background

The City of Anaheim is located in Orange County, in Southern California.

Anaheim Public Utilities (Anaheim) is responsible for providing electric and waterservices for the local community. Anaheim began to serve its municipalcustomers in 1895, serving a customer base of 145 incandescent bulbs and 22arc lamps. Anaheim has grown to a population of over 335,000 and a serviceterritory of 48.2 square miles. Anaheim presently serves over 109,000 electricmeters (85% residential, 14% commercial and industrial, 1% other) and over61,000 water meters (87% residential, 10% commercial and industrial, 3% other).

Anaheim sells in excess of three million megawatt-hours (MWh) per year with ahistoric system peak demand of 578 megawatts (MW). Anaheims resourceportfolio has ownership in generating resources throughout the Western United

States that include coal, natural gas, nuclear, hydro and wind power. Anaheimowns and operates its own 48 MW combustion turbine plant within the Cityboundaries for peaking capacity. Anaheim has adopted a Renewable PortfolioStandard, and will subsequently take power from geothermal and landfill gas inaddition to wind resources. Local solar generating resources are also promoted,including photovoltaic systems on top of roofs of residential and commercialcustomer facilities, as well as at municipal facilities.

1.2 Project Objectives

When evaluating small-scale thermal energy storage (TES) as a potentialcustomer application, Anaheim considered the following project objectives:

1. To reduce the utilitys overall system peak demand Anaheim pridesitself in offering high quality services to its customers at low costs. In orderto continue to serve the customer base without increasing rates, Anaheimmust plan a power resource strategy that mitigates higher cost power.TES represents one way to encourage small commercial customers tocontribute towards peak demand reduction that ultimately helps the utilitygain efficiencies in power purchases by pushing peak demand into off-peak hours.

2. To develop TES as a product offering for small commercial customerclass In recent years, Anaheim has made a concerted effort to tailorprograms and offerings for small commercial customers that includes anenergy efficiency program that offers turnkey energy audit and efficiencymeasures installation. TES installed on refrigerant-based, packageheating, ventilation, and air conditioning (HVAC) systems along with a


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Application of a Small-Scale Thermal Energy Storage System Anaheim Public Utilities

2

time-dependent rate option is a potential program offering that helps theutility, and helps customers lower their energy bills.

3. To gain first-hand experience with the design, permitting,installation, and operation of a small-scale TES system. In preparation

for future installations of such system, this demonstration project serves tofamiliarize City staff with the requirements for small-scale TES. The TESsystem and the existing HVAC system were instrumented to collect dataand compare performance metrics. Also, the system is installed at a Cityfacility, and an assessment from a users perspective will help inevaluating comfort.

1.3 TES Theory of Operation

In general, TES is not a new technology or concept. The operating principle for

air conditioning application is to store a cooling medium during off-peak hours, forutilization in space conditioning during on-peak hours. The cooling medium maybe chilled water, ice, or eutectic salts. This is a regenerative cycle, and severaldifferent technologies have been developed. Traditionally, TES has been appliedto larger HVAC system due, in part, to the capital-intensive nature of aninstallation. Target applications have been those that had a substantial enoughair conditioning load and corresponding electric bills to offer a reasonablepayback.

By operating the system to create and store the cooling medium during off-peakhours, the majority of the energy consumption is removed from the facilitys peak

demand. For the facility to take advantage of this technology, a time-dependentelectric rate is required to provide economic benefit to the customer. Such a ratewould incentive lowering on-peak demand to off-peak hours. Figure 1 shows thegeneral impact to a small commercial facilitys load profile.

Midnight Noon Midnight

6 kW Peak

Baseline

Ice System4.5 kW Peak

De

mand

Figure 1. Demand Profile of a Facility Before (top) and After (bottom)Implementation of TES


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The customer receives several benefits for pushing demand to off-peak hours:

1. The customers comfort level is not compromised, since the same amountof cooling is delivered when needed during the warmest periods of theday.

2. The HVAC system operates during off-peak hours, when temperatures aregenerally lower and the system operates more efficiently3. The HVAC system does not have to be sized for the super-peak periods

when demand is at its highest due to operation of TES, and may thereforeallow for downsizing of the HVAC system.

4. The customer may take advantage of lower off-peak rates.

1.4 Utili ty Perspective

Many utilities offer time-of-use (TOU) rates that encourage customers to shift

peak demand. Typically, TOU rates are structured with an on-peak rate that issubstantially higher than the standard rate, and an off-peak rate that is lower thanthe standard rate, which works to provide financial incentives to customers whoare able to transfer load to off-peak hours.

For utilities that have substantial air conditioning loads that contribute to systempeak demand, TOU rates helps to flatten the system load profile. This can beutilized to shape forecasts for power purchases that reduce the higher cost of on-peak resources, and helps increase off-peak demand. Thus, TES effectivelyassists utilities in managing their power resource without significantly impactingoverall revenue. This is an important consideration when customers consider

cogeneration or other energy efficiency alternatives. In instances where additionof transmission or distribution capacity may be difficult, TES offers a possiblesolution that helps to delay required upgrades or additions.

The effective result also has an environmental benefit, as dependency onpeaking plants, which may have higher air emissions, is reduced. In a studysponsored by the California Energy Commission, which evaluated TES impactstowards air emissions, the study concluded that TES could result in saving 1.6tons of NOx per day in the [South Coast Air Quality Management District]SCAQMD. These NOx savings are equivalent to the savings from substitutingalmost 100,000 electric vehicles for gasoline vehicles.1

1Source Energy and Environmental Impacts of Thermal Energy Storage, California EnergyCommission, Report P500-95-005, February 1996.


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2.0 PROJECT METHODOLOGY

2.1 TES System Descr iption

The project methodology was to gain first-hand experience with small-scale TES

by designing and installing a system in a retrofit application. The TES systemselected for use in Anaheims demonstration is the Ice Bear 50 unitmanufactured by Ice Energy, LLC. The Ice Bear is a refrigerant-based, internalmelt, ice-on-coil, TES device that provides approximately 45 ton-hours of coolingcapacity. It is capable of reducing as much as 10 kW (typical) of peak demandand shifting approximately 50 kilowatt-hours (kWh) to off peak hours.

By making ice during the evening, the unit uses only 300 watts for recirculatingpumps, along with the existing circulation fans to deliver cooling to the facility.This regenerative cycle repeats daily, and no additional water needs to be addedin the fully contained package of approximately 6 x 5 x 5 (see Figures 2 and 3).

Figure 2. Ice Bear 50 TES System (cour tesy of Ice Energy, LLC)

A condensing unit is included as part of the package to provide the coolingnecessary to freeze the water stored inside the Ice Bear. It is a standard, off-the-shelf unit. In certain applications, the existing HVAC may be able to supply therequired cooling for the TES system. In Anaheims application, a separatecondenser was required for comparative data collection, and also becausecooling was required throughout the day and evening.


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Figure 3. Ice Bear Unit (right) and Standard Condensing Unit (left)

Ice Energys Ice Bear 50 product complements the refrigerant-based market.The Ice Bear is an internal melt, ice-on-coil, thermal energy storage system thatspecifically targets package air conditioning that is ubiquitous throughoutcommercial and residential facilities in the United States. The components arelow-cost, off-the-shelf commodities in a form factor that is easy to install, operateand maintain.2

The product brief is included as Appendix A. The following table summarizes theunits specifications.

Table 1. Ice Bear 50 Product Data

Cooling Performance

Nominal Tonnage 5 tons 17.5 kW

Total Cooling Capacity 45 ton Hrs 540 kBtu / day

Latent Heat Capacity 42 ton Hrs 504 kBtu / day

Maximum Cooling Load 10 tons 120 kBtu / hr

Peak Power 0.5 kW

Energy Performance

Energy to build ice(1) 48 kWh / day

2Ice Energy website, www.ice-energy.com.


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Energy to discharge ice 4 kWh / day

EER (Btuh / Watts ) 10.4

Physical Properties

Refrigerant Charge (HCFC-22) 31 lbs.

Dimensions (W x L x H)

Energy Storage Module 73x73x63 inches 185x185x160 cm

Total Assembly 129x80x63 inches 320x203x160 cm

Shipping Weight

Energy Storage Module 800 lbs 363 kg

Condensing Unit & Piping 300 lbs 136 kg

Frame 420lbs 191 kg

Total 1520 lbs 689 kg

Weight Filled

Energy Storage Module 6125 lbs 2778 kg

Condensing Unit & Piping 300 lbs 136 kg

Frame 420lbs 191 kg

Total 6845 lbs 3105 kg

Water Volume 85.3 cu ft 638 gal.

Electrical Requirements 20 amp single phase circuit

Condensing UnitNominal Tonnage 5 tons

Approved Models

Trane 2TTB0060A


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American Standard 2A7B0060A


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Evaporator Coil Recommendations

TonnageAs required at 50oF evaporatortemperature

Tube Diameter (in) 3/8 in. (or smaller)

2.2 Site Description

An initial set of site surveys were conducted at several locations in the City ofAnaheim and the most suitable location was found to be an Anaheim FireStation. Site surveys evaluated compatibility of the existing package airconditioning system, energy and thermal profile, available space, proximity toelectric service and existing ducts, accessibility, and security/vandalism risk.

Figure 4 shows the fire station facility selected for the demonstration.

Figure 4. Anaheim Fire Station

2.2.1 Site Characteristics

The fire station facility features two large bays for parking of fire engines. Thespace conditioned areas include a dormitory, dispatch center, offices,kitchen/dining area, and lounge. See Figure 5 for the layout of the site.


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Parking

Gate

MechanicalEquipment Well

Truck Bays

Truck Apron

OutdoorPatio

ElectricalRoom

Generator

C

Refrigerant Lines(rooftop)

Condensing Unit

ICE

Ice Bear Unit

Existing 5-TonPackage Units

AC1

AC2

Driveway

T2

T1

Lounge/ KitchenAreas Area 2: Dormitory,

Offices, DispatchCenter

Storage

Bushes

PlantedArea

FLOW

FLOW

FLOW

FLOW

Figure 5. Fire Station Site Layout

The space conditioning is served by two 5-ton package unit. One unit serves thekitchen and lounge areas, and the second unit serves the dormitory, offices anddispatch areas. The latter air conditioning system was the test case for the TESinstallation. The two systems are independent of each other, as they arecontrolled by separate thermostats. The air conditioning units (see Figure 6) arelocated on the rooftop, in a mechanical equipment well. The ducting is directlybelow the units.


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Fire Station Energy Profile

0

50

100

150

200

250

300

350

Jun-0

4

Ju

l-04

Aug-0

4

Sep-0

4

Oc

t-04

Nov-0

4

Dec-0

4

Jan-0

5

Fe

b-0

5

Mar-

05

Apr-

05

May-0

5

DailyEnergy(kWh

/day)

0%

10%

20%

30%

40%

50%

60%

70%

LoadFactor

Daily Energy Load Factor

Figure 7. Fire Station Daily Usage and Load Factor (by billing period)

The facility uses more energy during the summer months due to high airconditioning usage, and less during the winter months. Other loads in the facilityinclude lighting, an air compressor, computers and communications equipment,kitchen appliances, and various plug loads. The peak demand of 25.9 kWoccurred on September 5, 2004. As Figure 8 shows, the peak was reachedduring the late afternoon.

Fire Station Peak Day Profile

(Sept. 5, 2004)

0

5

10

15

20

25

30

0:00

2:00

4:00

6:00

8:00

10:00

12:00

14:00

16:00

18:00

20:00

22:00

Demand(kW)

Figure 8. Facility Energy Profile for Peak Day (Sept. 5, 2004)


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2.2.3 Site Requirements

The site required some preparation to install a housekeeping concrete padextension, clearing of some bushes, and repositioning of a small iron gate. TheIce Bear was located on a walkway along the side of the facility. The unit was

located to allow appropriate walkway and equipment clearances as required bythe building code. The gate allows personnel access from the street. Shouldequipment replacement be required, the walkway leads to the open truck apronarea in the back of the facility. Figures 9 and 10 show the walkway area prior toconstruction.

Figure 9. Fire Station Walkway Area (front view from street)


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Figure 10. Fire Station Walkway Area (rear view)

Because the facility is utilized throughout the day and cooling is required at night,the existing rooftop air conditioning was to stay in place and operational duringnighttime hours. Sequencing of the cooling schedule was to use the Ice Bearduring the day (between 11AM and 8PM), and then to switch over to the existingair conditioner at night, when the Ice Bear was recharging and making ice.

Another reason for the location of the Ice Bear was due to a request by the CitysPublic Works Facilities Maintenance group who maintains all buildings. Forpurposes of easy access and to minimize potential for roof leaks, the unit was

installed on the ground.

During evaluation, both the Ice Bear and the existing air conditioning unit wereequipped with datalogging equipment to monitor performance. The facility has aload profile meter in place of a conventional utility meter to allow energy usage tobe captured in 15-minute intervals. The meter uses a paging module to reportdata back to the utility on a nightly basis, allowing next days data to be viewedand analyzed. The data gathered by the monitoring equipment was used toevaluate the Ice Bear operation and energy performance.

2.2.4 System Design

The Ice Bear system design inserts a new evaporator coil inside the existingductwork. As Figure 11 shows in block diagram form, the Ice Bear utilizes aseparate condensing unit to form ice. Refrigerant lines loop to the newevaporator coil. This allowed the existing ducts and fan to operate as normal,with no alterations made to the existing system, except where the new


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evaporator coil was installed. The green colored blocks represent the additionalequipment installed for this project.

This design allowed the existing unit to continue to operate during the eveninghours when the Ice Bear was making ice. Also, since the Ice Bear was a beta

system, it allowed for maximum flexibility in the event that extended maintenancewas potentially required. To prevent possible air conditioning interruptions to thefacility, the design allowed for switching back to the existing system withoutinconveniencing the occupants. To ensure proper control of both units thethermostat was scheduled for two time periods: on-peak, in which the Ice Bearwould operate, and off-peak, in which the existing system would operate. Figure12 shows the configuration of the installation.

Existing Packaged

Air ConditioningUnit

Air Distribution

(Ducts)

Existing PackagedAir Conditioning

Unit

Evaporator Coil(New)

Air Distribution(Ducts)

Ice Bear ThermalEnergy Storage

Condenser Unit

Existing HVAC System

HVAC System Includ ing TES

Figure 11. TES System Block Diagram


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Figure 12. TES Installation Diagram

2.3 Project Implementation

2.3.1 Approval Process

Due to the Ice Bear unit being a new technology, other departments involved withthe approval process had to be educated on the system, its effects on thebuilding and existing equipment, whether or not there were any hazardousmaterials used, and aesthetics. In order to familiarize Anaheims Building andPlanning Divisions with the technology, Ice Energys architect helped to explainthe system and provide appropriate documentation. Figure 13 shows a flowchartof the approval process for this project.

Ice Bear Unit

CondensingUnit

EvaporatorCoil

Existing Roof Top Unit

RefrigerantLines


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START

City Council approval of

agreement with Ice Energy

Submit plans andspecification for Building

Division approval

Submit plans to PlanningDivision

PlansAccepted?

Provide additional equipmentinformation

Prepare Site and InstallTES System

Commission TES Systemand Receive Inspection

Approval

COLLECT DATA

Figure 13. Anaheim Approval Process Flow Chart

For the Building Division, a set of plans included the site layout, product brief,specifications, and photos from the site. In the discussion, the matter of whetheror not the Ice Bear impinges on the existing air conditioning system was brought


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Figure 14. Site Clearing

Figure 15. Placement of TES and Condensing Unit onto Concrete Pad


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Figure 16. Installation of New Evaporator Coil

Figure 17. Refrigerant Lines on Facility Rooftop


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Figure 18. Refrigerant Lines Along Wall, and Condenser Electric Disconnect


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Figure 19. Aluminum Tape Wrapped Around Refrigerant Line Insulation

Figure 20. Ice Forming on Coils Inside Ice Bear Unit


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Figure 21. Two-Stage Thermostat

Figure 22. Completed Installation


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3.0 Results

3.1 Unit Data Analysis

Results indicate that the Ice Bear TES system was effective in reducing peakdemand. Figures 23 and 24 show the demand reduction by measuring demandbefore and after the TES installation. Figure 23 shows that the peak demandreached 7 kW in the late afternoon, which is consistent with the characteristics ofthe facility energy profile shown in Figure 8. In addition, the duty cycle of thecompressor is apparent from the graph. During the warmest parts of the day, thecompressor is cycling consistently and frequently in order to meet the coolingload.

Before Ice Bear, Hot Day (110 Roof Top)

0.000

1.000

2.000

3.000

4.000

5.000

6.000

7.000

12:00:00 AM 4:48:00 AM 9:36:00 AM 2:24:00 PM 7:12:00 PM 12:00:00 AM

RTU

Figure 23. Demand Profile Prior to Ice Bear Installation (Roof Top Unit)

In comparison, Figure 24 shows the demand profile after the installation of theIce Bear. Note that the demand during the peak hours has dropped significantlyfrom 7 kW to 0.3 kW. This equates to about 95% demand reduction for a similarweather day. The Ice Bear condensing unit (green line) creates ice during off-


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peak hours. Note that the demand required for the condensing unit is lower(approximately 3.5 kW), and the unit does not continuously cycle on and off.

Figure 24. Demand Profile After Ice Bear Installation

In order to determine the difference in energy between the Ice Bear and existingair conditioning system, calculations were performed to estimate the energyusage and duty cycles as if the existing air conditioning system were still running.The estimated energy consumption profile was developed by using run time datafrom the Ice Bear and correlating projected energy to temperature data. Figure25 shows dotted lines that represent the estimated air conditioning profile over a24-hour period (from 9AM to 9AM) for October 14, 2004 on a day in which themaximum ambient temperature was 87oF.

In terms of energy savings, data in Table 2 shows that the energy is not reducedby a significant amount. The energy savings over a 2 week span was 22 kWh (or4.2%) against a 528 kWh baseline. The energy efficiency is a result of thecompressor operating more efficiently at night in a more uniform manner than theconstant starting and stopping during the day that the traditional system. From autility standpoint, the energy neutral aspect is a positive feature of thetechnology, since it builds up off-peak load, and helps to level out the utilityssystem peak profile.


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Combined Demand Profile (October 14, 2004)

0

1

2

3

4

5

6

9:00

1

1:00

1

3:00

1

5:00

1

7:00

1

9:00

2

1:00

2

3:00

1:00

3:00

5:00

7:00

Demand(kW)

AC - Actual

AC - Projected

Ice Bear

Figure 25. Combined Demand Profile (Ice Bear and Existing Air Conditioner)

Table 2. Daily Energy Totals

Day

MaximumAmbient

Temperature(F)

MinimumAmbient

Temperature(F)

EnergyBefore IceBear (kWh)

EnergyAfter Ice

Bear (kWh)Difference

(kWh)

10/7/2004 84 56 62.2 56.7 5.510/8/2004 87 57 58.5 57.6 0.9

10/9/2004 78 59 47.2 43.3 3.9

10/10/2004 72 53 31.2 34.4 -3.2

10/11/2004 77 59 50.1 45.8 4.3

10/12/2004 83 63 50.0 47.8 2.3

10/13/2004 79 58 38.9 41.4 -2.4

10/14/2004 87 61 52.8 52.1 0.7

10/15/2004 77 61 35.7 38.8 -3.1

10/16/2004 66 58 22.0 20.7 1.4

10/17/2004 69 63 31.7 28.3 3.4

10/18/2004 70 62 25.1 24.3 0.8

10/19/2004 66 62 22.5 14.5 8.0

3.2 Facility Data Analysis

At the facility level, the results of the TES system can also be seen graphically.Figure 26 shows two sample days of billing meter data. Facility data is shown forSeptember 5, 2004 before the Ice Bear was installed, and September 23, after


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the Ice Bear was installed. The differential in demand is generally 7 kW, from 20kW down to 13 kW, which corresponds to the TES equipment differential.

Comparison of Facility Energy Consumption(Before and After TES)

0

5

10

15

20

25

30

0:0

0

2:0

0

4:0

0

6:0

0

8:0

0

10:0

0

12:0

0

14:0

0

16:0

0

18:0

0

20:0

0

22:0

0

Demand(kW)

9/5/2004 9/23/2004

7 kW

differential

Figure 26. Facility B illing Meter Before and After TES Installation

In reviewing data over the course of several months, the facility meter shows inTable 3 that the there was a slight energy efficiency improvement. There wasalso a slight decrease in the peak demand for the given months. This datareinforces the unit data analysis in Section 3.1, which showed significant demandreduction during on-peak hours and the slight energy efficiency improvement.Because the facility is equipped with two separate air conditioning units, theoverall demand reduction would have been greater if both units were retrofittedwith TES systems. As Table 3 shows, over the 4 month period, there was a totalbill savings of $97.88, or $24.47 per month.

Table 3. Facility Billing Summary Comparison

Feb-May DaysEnergy(kWh)

DailyEnergy

(kWh/day)

PeakDemand

(kW) Actual Bill

2004 (Before) 119 28,920 243.0 23.6 $2,795.64

2005 (After) 119 27,905 234.5 20.8 $2,697.76

Savings 1,015 2.8 $97.88


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3.3 Comfort and Availabili ty

The Ice Bear has operated since September 2004 with no major issues in termsof operation and maintenance. The only significant change that occurred duringthe course of the project was the fact that two thermostats were requested by

Anaheims Facility Maintenance group. The reason was to keep the existingsystem and the Ice Bear separately controlled in the event that the TES systemwould be decommissioned in the future. The thermostats were each programmedwith schedules to allow the Ice Bear to operate during the day and the existingsystem to operate at night. Since Fire Department staff occupies the facility atnight, there is still a cooling load during off-peak hours. Operation of thethermostats caused some confusion and in some cases both units wereoperating at the same time. To alleviate this, one thermostat was removedcompletely, and the programming was scheduled to take advantage of the two-stage configuration.

Throughout the demonstration period, Ice Energys staff periodically checked onthe system to ensure that the unit was operating properly. Other than thethermostat issue, the TES system performed very reliably. During theconsolidation of the two thermostats, there were several complaints from the FireDepartment staff concerning building temperatures. This was alleviated by tuningthe system and removal of the second thermostat. As a result of these actions,the comfort level improved significantly. Ice Energy currently has a technicianlocated in Southern California to address any future issues.

4.0 Future Plans and Applicability

The TES system continues to operate at the fire station. Anaheim will continue tomonitor the system and evaluate operation and maintenance for a full summer.Several site visits have been conducted for interested parties including otherutilities. As a result of Anaheims project, the Southern California Public Power

Authority (SCPPA), of which Anaheim is a member, has initiated a demonstrationprogram with other area municipal utilities. Up to 10 Ice Bear units will beinstalled at various locations to further evaluate the technology.

Of interest will be the results which may vary due to the different facilities, coolingloads, and regional weather patterns. For example, units installed in the dry

desert climate with higher temperature differentials are expected to have higherefficiency gains than moderate, coastal climates. These anticipated operationlevels will be quantified for member agencies through data collection andevaluation. An additional outcome of the SCPPA program will be to furtherinvestigate funding sources, rates and incentives that may help accelerate theadoption of small-scale TES in Southern California.


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The applicability of small-scale TES technology suits utilities with high on-peakdemand that is comprised of high air conditioning usage. Utilities have typicallymet load growth with some method of generation and transmission planning.

Additionally, most utilities have a level of energy efficiency programs to helpcustomers lower their bills and lower overall consumption. Other methods of

mitigating peak demand include demand response programs, time-dependentrates, and distributed generation incentives (e.g. photovoltaics and in somecases, co-generation) are promoted to varying levels by utilities. TES is a smallpart of this mix at present; however, with the inclusion of time dependentvaluation in the 2005 revision of Californias Title 24 Building Code, shifting peakload is encouraged. The California Energy Commission (CEC) adopted the 2005changes to the Building Energy Efficiency Standards, for a number of reasons,including the objective:

To emphasize energy efficiency measures that save energy at peakperiods and seasons, improve the quality of installation of energy

efficiency measures, incorporate recent publicly funded building scienceresearch, and collaborate with California utilities to incorporate results ofappropriate market incentives programs for specific technologies.4

The CEC recognized that energy use during peak demand is valued differentlythan energy during off-peak hours. As a result, the CEC has developed TimeDependent Valuation (TDV).

Beginning with the 2005 Standards, the currency for assessing buildingperformance is time dependent valued (TDV) energy. TDV energyreplaces source energy, which has been the currency since the CEC firstadopted standards in 1978. TDV, as the name implies, values energydifferently depending on the time it is used. This means that electricitysaved on a hot summer afternoon will be worth more in the complianceprocess than the same amount of electricity saved on a winter morning.The value assigned to energy savings through TDV more closely reflectsthe market for electricity, gas, propane and other energy sources andprovides incentives for measures, such as thermal storage or daylightingthat are more effective during peak periods.5

Anaheim is also evaluating the possibility of including residential-scale TES fromIce Energy to be included as a portion of a new housing development.Discussions are ongoing with the home builder to determine the level of interest.Part of a demonstration project will focus on the Title 24 calculations for homeswith and without TES.

4http://www.energy.ca.gov/title24/2005standards/index.html, California Energy Commission

website.52005 Building Energy Efficiency Standards, Nonresidential Compliance Manual, CaliforniaEnergy Commission, CEC-400-2005-006-CMF, p.7.2-3.


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6.0 Budget

The project was completed within the allotted project budget. Of note, becausethe pre-production unit operated exceptionally well, it was decided that anupgrade to the production unit was not necessary, as all the major components

are the same. Rather, an extended warranty was provided to cover the pre-production as if it were a new installation.

Item Descrip tion Budget Expendedto Date

DEEDGrant

1 Ice Energy (Monetary)1.1 Pre-Production Unit $10,000 $10,0001.2 Production Unit $10,0001.3 Datalogging equipment $3,000 $3,0002 Ice Energy (In Kind)2.1 Project Management [80

hours @ $100/hr]

$8,000 $8,000

2.2 Construction Management[20 hours @ $100/hr]

$2,000 $2,000

2.3 Design and Engineering[20 hours @ $150/hr]

$3,000 $3,000

2.4 Data Analysis andReporting [60 hours @$150/hr]

$9,000 $9,000

3 Anaheim (Monetary)3.1 Installation &

commissioning$10,000 $10,000 ($10,000)

3.2 Building permit fees $500 $1663.3 Load profile meter and

installation$1,000 $1,000

4 Anaheim (In Kind)4.1 Project Management [120

hours @ $50/hr]$6,000 $6,000

4.2 Contract Administration[40 hours @ $50/hr]

$2,000 $2,000

4.3 Misc Staff Labor (settingup meter profile forInternet accessibility,

other Department labor)[40 hours @ $50/hr]

$2,000 $2,000

TOTALS $66,500 $56,166 ($10,000)


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7.0 Conclusions

The Ice Bear TES system was successful in shifting on-peak demand to off-peakhours. It was retrofitted into an existing building and provided the cooling loadwithout sacrificing comfort for the occupants. The fact that the technology is now

available in a small form factor and is recognized in Californias new buildingcode demonstrates that TES can be widely deployed to package air conditionerthroughout the United States. Utilities may benefit from this technology by usingTES to shape system load profile. Anaheim will continue to investigate thetechnology through its demonstration at the fire station and by monitoring theadditional deployments by other municipalities. Based on those results, Anaheimmay provide up-front incentives to help reduce the capital costs in addition topromoting time-of-use rates which helps provide a return on investment tocustomers.


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Appendix A. Ice Bear Product Br ief


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Application of a Small-Scale

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