Heywood Road Project & MPRP Section 83 Sensitivity Analysis

Heywood Road Project & MPRPSection 83 Sensitivity Analysis

ISO-New England Planning Advisory Committee

November 19, 2008

Heywood & MPRP Sensitivity Analysis

• Issue

– Heywood Road (formerly Benton) Project (PPA CMP-06-T13) includes an increase of the sag-limited rating of Section 83 between Wyman Hydro & Section 83C tap

– Detailed design [using Light Distance And Ranging (LiDAR) data] has indicated that re-rating is expensive, nearly $10 million

– A new 115 kV line parallel to Section 83 between Wyman Hydro and the Section 241 (Rice Rips) tap would be $19.6 million – there is room on the existing Right-of-Way (ROW) for a new line

– Heywood Road Substation will enter service this winter

2

• Preliminary Analysis pre-MPRP Conclusions, June 2008

– A new 115 kV line parallel to Section 83 would reduce line losses by 4 to 6 MW under peak load conditions

– Northern Hydro export capability will be increased with a new 115 kV line parallel to Section 83

– MPRP system upgrades should be re-assessed in the Waterville/ Winslow/Skowhegan area with a new 115 kV line parallel to Section 83


3

• Study Objectives for MPRP Sensitivity Analysis

– Re-assess the MPRP system upgrades in the Waterville/ Winslow / Skowhegan area based upon

• New 115 kV line parallel to Section 83 between Wyman Hydro and Section 241 (with a new tap to Rice Rips)

• Conversion of Maxcys (Coopers Mills) 115 kV straight bus to a breaker-and-a-half configuration


4

• Original MPRP system upgrades in the Waterville / Winslow / Skowhegan area:– New 115 kV line from Albion to Winslow (Section 245)– 115 kV Line Rebuilds to create space in ROW for new

construction• Section 84 (Albion to Winslow)• Section 67A (Albion to Heywood Rd, new Section 259)

– Re-rate of 115 kV from Heywood to Rice Rips (Section 241)– New 345/115 kV Albion Road Substation

• Breaker-and-a-half 115 kV configuration terminating Sections 67, 67A, 84, new Section 245 to Winslow, and 345/115 kV transformer

– 115 kV capacitor bank installations• 50 MVAR at Heywood Road (increase from 20 MVAR today)• 50 MVAR at Winslow


5

• Study Assumptions– Base cases originated from MPRP Needs Assessment

– New 115 kV line from Wyman Hydro to Section 241 (with a tap to Rice Rips)

• 39 miles of 1113 KCM ACSR conductor

• Interconnect with Section 241 with new tap 2.6 miles from Heywood Road

– Section 83 will not be re-rated

– Relocate Section 83B (Lakewood) Tap to new line


6

Heywood

Wyman Hydro

LakewoodSection 83B

Section 241

SappiSection 83C

21.5 mi

12.3 mi

17.3 mi

3.3 mi

2.6 mi

29 mi

NEW

0.5 mi

Rice Rips


7

• Analysis used MPRP Northern Alternative N5 with modified Waterville/Winslow/Skowhegan facilities:– Maxcys (Coopers Mills) 115 kV with breaker-and-a-half

configuration

– All other N5 upgrades in service except for:• Winslow and Heywood capacitor additions

• Rebuild of Section 259 (Albion to Heywood), formerly part of Section 67A

• Rebuild of Section 84 (Albion to Winslow)

• New Albion to Winslow 115 kV Line


8

• N-1 and N-1-1 Assessment of Thermal Performance

– N-1: Section 84 (Albion to Winslow) overloaded for loss of Section 259 (Albion to Heywood)

– N-1-1: No additional thermal concerns

– Section 84 (Albion to Winslow) requires rebuild

• N-1 and N-1-1 Assessment of Voltage Performance

– N-1-1 Low Voltage Concerns with Albion T1 or Maxcys T3 Outages with other contingencies

– 25 MVAR of capacitors at Winslow 115 kV meets N-1-1 voltage criteria (previously two MVAR capacitor banks)


9

• Conclusions

– Re-assessment of MPRP reinforcements in the Heywood area showed that addition of the new parallel line, with relocation of Section 83B (Lakewood) Tap to Section 241 and a Maxcys 115 kV breaker-and-a-half yard, reduced the system upgrades required to meet N-1-1 criteria in the Heywood area

– The following system upgrades will no longer be required for MPRP

• 30 MVAR additional capacitors at Heywood

• 25 MVAR of capacitors at Winslow

• New 115 kV Section 245 (Albion to Winslow)

• Rebuild of 115 kV Section 259 (Albion to Heywood)


10

• Conclusions, cont.

– The following system upgrades are still required for MPRP in the Waterville/Winslow/Skowhegan area

• Rebuild of 115 kV Section 84 (Winslow to Albion)

• Re-rate of 115 kV Section 241 (Heywood to Rice Rips)

• New 345/115 kV Albion Road Substation

– Breaker-and-a-half 115 kV configuration for termination of Sections 67, 67A, 84, and 345/115 kV transformer

• 115 kV capacitor bank installation

– 25 MVAR at Winslow (previously two 25 MVAR capacitor banks)


11

Heywood

Rice

Wyman Hydro

Sappi

Winslow

Proposed Heywood Area Configuration

Williams

Bigelow

Detroit

20 MVAR

Albion Rd

Rips

F

D

BE

C

A

K66-1K83-5NEWK63-1K215-1

LakewoodSection 241B

Section 241A

Se

ctio

n 8

3

Se

ctio

n 2

42

Section 259

Section 84

Section 83C

25 MVAR

(formerly 67A)

(fo

rme

rly

83

)

Units #1-3Harris

K222-1

- Proposed Upgrade

- Existing

K2

59

-4

K6

7-3

KT

1L

-2K

25

9/6

9

KT

1L

-1

K2

57

-1

K8

4-3

K2

57

/84

K2

58

-1

K2

58

/24

5

K3

02

4-4

E1

KT

1H

-1

K3

02

4/T

1H

Maxcys

Detroit

Orrington

Se

ctio

n 6

7

Se

ctio

n 2

57

Se

ctio

n 2

58

Section 3024

Section 3023

Maxcys

T1

Lakewood Tap Relocated

(Rebuild)

25 MVAR

NEW

(Rebuild)

Se

ctio

n 2

41

2 - 18 MVAR

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Item Description Estimated Cost, millions

A.1 Re-rate existing section 83 $10.2

A.2 New 115kV line Section 245, Albion Rd to Winslow1 $3.2

A.3 Rebuild Section 259 (formerly Section 67A), Albion Rd to Heywood1 $3.4

A.4 Winslow S/S: Add line terminal and capacitor bank $3.4

A.5 Heywood Road S/S: Add capacitor bank $1.4

A.6 Wyman Hydro S/S: Add capacitor bank $1.4

Total $23.0

1 Items A.2 and A.3 adjusted downward by $330k/mile to account for differences in estimating assumptions, as compared to A.1 and B.1

Option A: Re-rate Section 83

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Option B: New 115kV Line parallel to Section 83

Item Description Estimated Cost, millions

B.1 New 115kV line parallel to Section 83, Wyman Hydro to Section 241 $18.5

B.2 Wyman Hydro S/S: Add line terminal $1.1

Total $19.6

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• Combined Results of Heywood Road and MPRP analyses

– Estimated cost savings of not building these MPRP facilities = $12.8 million

– Net cost savings of building a new parallel 115 kV line from Wyman Hydro to Section 241 = $3.6 million

– New 115 kV line will reduce losses

– New 115 kV line will increase Wyman Hydro area export capability


15

• Next Steps

– Conduct PPA sensitivity analysis of Heywood Road with a new 115 kV line parallel to Section 83, rather than re-rating Section 83

– Conduct PPA sensitivity analysis of this new 115 kV line along with changes for MPRP

– Submit PPAs for changes

– Submit Transmission Cost Allocation (TCA) application for the Heywood Road Project with the cost credit of facilities avoided with MPRP and this new 115 kV line

– Submit Maine PUC Certificate of Public Convenience and Necessity for this new 115 kV line


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Documents

Heywood Road Project & MPRP Section 83 Sensitivity Analysis