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Central MA Transmission Upgrades: TCA Revision

Central MA Transmission Upgrades: TCA Revision. NEPOOL Reliability Committee June 16, 2009. Central MA Upgrades - History . 18.4 applications approved in April 2004 Install 69 kV circuit breaker at Woodside Replace Millbury T1 and T2 115-69 kV transformers

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Central MA Transmission Upgrades: TCA Revision

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  1. Central MA Transmission Upgrades:TCA Revision NEPOOL Reliability Committee June 16, 2009

  2. Central MA Upgrades - History 18.4 applications approved in April 2004 • Install 69 kV circuit breaker at Woodside • Replace Millbury T1 and T2 115-69 kV transformers • Install two additional 115-69 kV transformers at Pratts Junction, replace 69 kV circuit breakers, and transfer one-half Prospect Street load • Wachusett 345-115-69 kV substation • Reconductor 115 kV lines O-141N, P-142, W-175 • Reconductor 69 kV lines M-39, N-40 • Replace 115 kV circuit breaker at Rolfe Ave • Upgrade W. Boylston protection systems • Replace W-23E 69 kV line disconnect

  3. Central MA Upgrades – TCA History • Initial TCA (15.5) – RC Action deferred in June 2004 Based on conceptual cost estimations, the initial TCA application submitted to RC in May 2004. • Revisions 0 & 1 – Approved in January 2005 Captured higher costs due to GIS instead of the originally scoped air insulated substation. Wetlands restrictions drove the design to GIS. • Revision 2 – Submitted now to capture “As-Built” costs Wachusett Sub commissioned March 2007. Punch List items extended into 2008 ($4.8M). Actual Costs tracking delayed.

  4. TCA & Project Timeline 2004 2005 2005 2006 2007 2008 2009 18.4 Approved Multi 15.5/TCA $43.4 M TCA - Rev 0 (Consolidated) $54.7 M TCA - Rev 1 Approved $54.7 M TCA - Rev 2 “As Built” $69.7 M Project Construction extended into 2008 - invoice processing/punch list closeout items, - accounting retrieval/summary time – into 2009

  5. Millbury Substation Upgrades Scope: Replace existing T1 and T2 (115-69 kV) with larger transformers Millbury upgrades completed in 2005 Cost Estimate: 1.50 M Actual Cost: 1.17 M Favorable construction resulting in reduced cost

  6. W-175 115 kV Line Upgrade Scope: Reconductor 115 kV line. Line upgrades completed in 2004 Cost estimate: .474 M Actual cost: .858 M Reason for cost increase • Additional work to increase clearances to comply with NESC, • Static wire severely deteriorated requiring replacement, • Operational requirements and use of external resources at increased cost.

  7. O-141N & P-142 115 kV Line Upgrades Scope: Reconductor each 115kV line. Line upgrades completed in 2005 Cost estimate: 1.625 M Actual cost: 1.509 M Reason for cost decrease – favorable construction Minor design changes tended to increase costs as did operational requirements and use of external resources but were offset by favorable construction.

  8. O-141N & P-142 115 kV Line Protection Upgrades Scope: Upgrade protection on line/breaker at Wachusett. Line upgrades completed in 2007 Cost estimate: 0.440 M Actual cost: 1.357 M Reason for cost increase • All 115 kV equipment (Ngrid & Municipal) • Control building extension to accommodate additional equipment.

  9. M-39 & N-40 69 kV Line Upgrades Scope: Reconductor each 69kV line. Line upgrades completed in 2004 Cost estimate: 2.181 M Actual cost: 5.737 M Reason for cost increase • Property rights issues prevented original planned pole replacements/intermediate pole installations. Existing lattice towers instead reinforced, • Additional work to comply with NESC, • Static wire severely deteriorated requiring replacement, • Bird guards added to design, • Operational requirements and use of external resources at increased cost.

  10. Pratt’s Junction Upgrades Scope: Install two additional 115-69kV transformers & replace eight circuit breakers. Pratt’s Jct. upgrades completed in 2005 Cost estimate: 2.46 M Actual cost: 2.95 M Reason for cost increase • Temporary bus connections dictated by operational requirements • Restricted line outage windows causing overtime costs • Additional bus upgrade due to capacity, conductor strain & condition

  11. Wachusett Upgrades Additions to 115-69 kV and new 345-115 kV substation: • Wachusett 2nd 115-69 kV Xfmr completed in 2007 Cost estimate (rev.1): 2.53 M Actual cost: 3.63 M • Wachusett 345-115-69 kV completed in 2007 Cost estimate: 41.96 M Actual cost: 48.54 M • Original Cost Est. – non-GIS (total) 26.50 M (prior to bids being available) Reasons for cost increase • Turn key Project Costs (Rev #1) based on unsigned contracts, • Cost increases uncovered during detailed engineering design, • Contractual increases incurred, • Complexity of construction coordination involving multi-sites, scope, • AFUDC increase - Commissioning 4 month delay (relay & control cabinet delivery), • Increased material cost (see the next slide), • labor and other costs increase due to outage window constraints, • Increased contract vs. in-house crew costs (+25%)

  12. Wachusett Cost vs. Handy-Whitman Industry Cost Index Note: Handy-Whitman Index data taken from The Handy-Whitman Index of Public Utility Construction Costs report dated July, 2008 - Table E-1 “Total Transmission Plant” cost category.

  13. Breakdown of Actual Project Costs Other - includes AFDUC (3.3 M), Contractors (5.5 M), Miscellaneous (4.1 M) items

  14. Other Central MA Upgrades In Svc Estimate Actual • Woodside 69 kV 2004 0.700 M 2.953 M • Rolfe Ave Breaker 2005 0.366 M 0.402 M • W. Boylston Protection Upgrades 2007 0.440 M 0.877 M • Replace W-23E Disconnect 2004 0.020 M 0.108 M Reasons for cost increases • Scope creep – Inclusion of other than originally designed improvements added later in the preliminary engineering stage, • (e.g. protection systems at W. Boylston, structure, and foundation work). • Utilization of crude study grade cost estimations in the original application, • Operational outage considerations during construction (extra cost & temporary work), and • Changing material and labor market.

  15. Overall Cost Summary (2004 Estimates vs. Actual) In Svc Estimate Actual • Woodside 69 kV Breaker 2004 0.700 M 2.953 M • Wachusett 2nd 115-69 kV Xfmr 2007 2.530 M 3.634 M • Wachusett 345-115-69 kV 2007 41.959 M 48.542 M • O-141/P-142 Protection Upgrades 2007 0.440 M 1.357 M • Reconductor O-141N 2004 1.500 M 1.224 M • Reconductor P-142N 2005 0.125 M 0.285 M • Reconductor M-39 2004 1.000 M 3.227 M • Reconductor N-40 2004 1.181 M 2.510 M • Replace Rolfe Ave Breaker 2005 0.366 M 0.402 M • Reconductor W-175 2004 0.475 M 0.858 M • W. Boylston Upgrades 2007 0.440 M 0.877 M • Replace W-23E Disconnect 2004 0.020 M 0.108 M • Millbury T1 & T2 2005 1.500 M 1.173 M • Pratt’s Jct. Transf & Bkr Changes 2005 2.460 M 2.953 M Total: $54.696 M $69.748 M ($15.1 M Diff)

  16. Actual Costs – As Built • As Built costs exceed January 2005 TCA – Rev.1 values by ~27% ($15.1 M) • Requires TCA revision (> 10%) • Total “As Built” PTF cost: $69.7M (vs. $54.7M estimated in TCA – Rev.1) • Higher cost in general due to: • Scope of construction, • Required design changes, • Operational considerations during construction, and • Changing material and labor market.

  17. Transmission Cost Allocation • Construction now fully complete • Seeking Reliability Committee Approval of increased PTF construction costs actually incurred • Increased Amount: $15.1 M (actual dollars spent)

  18. Questions?

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