The Localized Substation Load Relief (LSLR) Program at Detroit EdisonPresentation by: Traci MacDonald

AEIC National Conference September 10-13, 2006

Silver Legacy Resort Casino - Reno, NV

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INTRODUCTION

Background on DTE’s Interruptible Air Conditioning (IAC) Program

Enhancements to the existing IAC program for development of the Localized Substation Load Relief (LSLR) program

LSLR Equipment

Results of the LSLR Pilot Test in 2004

Summer of 2005 and 2006 results

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IAC PROGRAM BACKGROUND

IAC program has historically been used for generation load relief

IAC tariff states that DTE can cycle service to IAC customers for reasons including, but are not limited to, maintaining system integrity, economics or when demand exceeds generation

Cycled interruptions of 15 minutes on and 15 minutes off allow for 30 minutes of cooling by A/C unit every hour

IAC customers can only be interrupted for a maximum of 8 hours/day

Eleven control towers in the DTE service territory are capable of transmitting interruption signals to all IAC customers

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EXISTING INFRASTRUCTURE

Having 11 towers allows DTE the flexibility to interrupt all 285,000 IAC customers or just target a specific geographic location to maximize interruption value

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IAC DEMOGRAPHICS

DTE currently has around 285,000 IAC customers

Expected load shed is approximately 1 kW for each IAC customer

About 250 MW’s of interruptible IAC load on the distribution system

There are close to one million households still remaining in the service territory as potential IAC customers

Sample and Control sites already out in the field which allow LR to analyze usage and study behavior patterns for this class

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OPTIMUM LOAD SHED WINDOW

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WHY LSLR? DTE occasionally exceeds distribution capacity limits on localized

circuits during the summer peak season and prior to LSLR, needed to rotate whole circuits to maintain system reliability

Started to focus on using IAC customer sites to provide relief for overloaded substations

The existing IAC program only needed minor tweaking to accommodate the LSLR goals

IAC program historically used to provide load relief at the generation level; now it can also be used to provide relief to localized overloaded distribution circuits

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LSLR PROGRAM GOALS

Minimize the need for whole circuit interruptions

Minimize inconvenience to customers by interrupting only IAC loads as opposed to whole house interruptions

Minimize revenue loss to DTE

Provide System Operators with an additional load management tool that can be used to shed load at substations nearing emergency levels

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ENHANCEMENTS

Replaced the use of a single control tower with a low power portable transmitter

Equipped an existing DTE vehicle with a transmitter, an antenna and a laptop with the Load Management System (LMS) software

Ability to drive directly to the substation(s) in need of load relief

Transmitter sends a 2 mile radius interruption signal to the area surrounding the substation and minimizes interruptions to IAC customers outside the substation service territory

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NEW INFRASTRUCTURE

Using the portable transmitter allows DTE to now target interruptions to localized substations and/or circuits versus a whole geographic area

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EQUIPMENT(Cost per Vehicle)

Remote Transmitter Controller (RTC): $4,000

Load Management (LMS) Software: $1,500

Antenna: $250

Laptop Computer: Stock Item

Transmitter: Stock Item

Company Vehicle: Stock Item

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LSLR HARDWARE

TransmitterRTC

Laptop

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Antenna

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2004 LSLR PILOT TEST

Purpose was to determine if a portable transmitter could be used to send an interruption signal to 2,121 IAC customers at Sloan substation

Predicted average load shed was 2.0 MVA

Average load shed was 1.8 MVA

Pilot Test was a success!

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SLOAN SUBSTATION(Load Shed Curve)

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ECONOMIC ANALYSIS

Economic Analysis (based on 2,121 customers):

Lost revenue due to whole house interruption/hour: $340 Lost revenue due to IAC interruption/hour: $150 DTE net savings/hour: $190 ($340 - $150) DTE net savings per 8 hours: $1,520

Payback:

Cost of Program per Mobile Vehicle: $5,800 LSLR Payback Period: approximately 4 days of use

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2005 LSLR PROGRAM

System Operators determined substations in need of relief and LR dispatched Telecommunications to the field

LR accompanied Telecommunications to the field and assisted with equipment set up and provided on-site training for the program

The LSLR team responded to all 47 LSLR requests by System Operators

Used LSLR on 23 occasions at 26 different substations

The LSLR team was successful in all but 1 request to reduce load at substation sites; that failure was due to an equipment malfunction

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2006 LSLR PROGRAM

System Operators resumed the role of dispatching the LSLR teams to the field

Telecommunications supported the field work for the LSLR program and LR provided oversight for the project

LSLR team responded to all 10 LSLR requests by System Operators and shed load on 8 occasions

Used LSLR on 8 occasions at 7 different substations

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LSLR CONCLUSION

LSLR reduces the number and duration of whole circuit interruptions and in some cases, eliminates the need for circuit rotation altogether

Increases customer satisfaction as customers would prefer cycled A/C interruptions rather than whole house interruptions

Relatively minor program costs with no additional labor expense

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SIGNIFICANT TAKE AWAYS

Strategic Load Research

Leveraging data and knowledge for Corporate success

LR recognized a problem and developed a value adding initiative to resolve