central ma transmission upgrades: tca revision
DESCRIPTION
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 - PowerPoint PPT PresentationTRANSCRIPT
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
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
2004 2005 2005 2009
Project Construction extended into 2008
- invoice processing/punch list closeout items,
- accounting retrieval/summary time – into 2009
2006 2007 2008
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 MActual cost: 3.63 M
Wachusett 345-115-69 kV completed in 2007Cost estimate: 41.96 MActual 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
Construction Costs Over Time(January Data)
0.00
0.200.40
0.60
0.801.00
1.20
1.401.60
1.80
Year
No
min
al In
crea
se
Handy-WhitmanIndexWachusettProjects
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
TCA Rev #2
Materials
Construction Labor
Engineering/ Design
Other
Cost CategoryRev.2 ($M)
Materials 9,433
Construction Labor 7,196
Engineering/Design 40,184
Other 12,935
Total: 69,748
Other - includes AFDUC (3.3 M), Contractors (5.5 M), Miscellaneous (4.1 M) items
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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 MWachusett 2nd 115-69 kV Xfmr 2007 2.530 M 3.634 MWachusett 345-115-69 kV 2007 41.959 M 48.542 MO-141/P-142 Protection Upgrades 2007 0.440 M 1.357 M Reconductor O-141N 2004 1.500 M 1.224 MReconductor P-142N 2005 0.125 M 0.285 M Reconductor M-39 2004 1.000 M 3.227 MReconductor N-40 2004 1.181 M 2.510 MReplace Rolfe Ave Breaker 2005 0.366 M 0.402 MReconductor W-175 2004 0.475 M 0.858 MW. Boylston Upgrades 2007 0.440 M 0.877 MReplace W-23E Disconnect 2004 0.020 M 0.108 M Millbury T1 & T2 2005 1.500 M 1.173 MPratt’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?