Transcript ELT Briefing on First Wave of Business Transformation

Substation Asset Strategy
Kevin Dasso, Senior Director
Engineering and Operations
IEEE/PES Annual Substations Committee Meeting
April 7, 2008
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Outline
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About PG&E
Challenges
Project Activities
Capital Investment Outlook
Trends
Bus Conversions
Mission Substation Rebuild
Questions
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About PG&E
PG&E
Service
Territory
Map
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•
PG&E serves 13 million people, or 1 out of
every 20 people in the U.S.
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70,000 Square Miles Service Territory, from
Eureka in the north to Bakersfield to the
south
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5 Million Electric Customers
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4 Million Gas Customers
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Transmission Voltages – 500, 230, 115, 70 &
60 kV
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Distribution Voltages – 35, 21, 17, 12 & 4 kV
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Substations - 748
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Electric Transmission Investment Profile
• Fastest-growing area of the business
• Investment driven by:
– System expansions as approved by the California
ISO
– Interconnections/upgrades to support new
generation
– Replacements, upgrades, and other life extension
programs to maintain capacity
– Reduction of grid congestion and Reliability Must
Run contracts
– Access to renewable generating resources
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Challenges
• Aging Infrastructure
– Replacements, upgrades, and other life extension
programs to maintain line capacity
• “Experienced” workforce
• NERC standards compliance
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Capital Expenditure Outlook
Projected capital expenditures average $900M for years 2008-2012:
Capital Expenditure Outlook ($MM)
1000
800
600
400
200
($MM)
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0
2008
2009
2010
2011
2012
Distribution Substation
$245
$207
$209
$206
$206
Transmission Substation
$338
$308
$314
$341
$361
Transmission Line
$257
$218
$515
$356
$402
Total (in $MM)
$840
$733
$1,038
$903
$969
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Trends
– Capacity growth
– Reliability enhancements
– Aggregation of future planned work at each facility in order
to effect wholesale reliability upgrades
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Bus Conversions -- Distribution
– The majority of existing
distribution busses are singlebus
• New installations are
designed with a ring bus ►
• Major equipment
replacement or capacity
expansion projects present
opportunities to convert to
ring bus
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Bus Conversions -- Transmission
– The majority of transmission
busses are double-bus /
single breaker
• New installations are
designed with breaker-anda-half (BAAH) bus ►
• Major equipment
replacement or capacity
expansion projects present
opportunities to convert to
BAAH bus
• Space constraints drive
toward GIS technology
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Mission Substation Rebuild
• Many aspects were considered:
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Operating Philosophy
Planned area upgrades
Reliability indexes and Outage statistics
Load balancing on 115 kV sources
Load planning and fault current levels
Available floor space, and construction
sequencing
– Construction clearance considerations—
load shifting and switching ability
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Mission Substation Rebuild
• Existing Substation Configuration:
– Built in 1947; expanded in 1958
– Indoor substation with 3 floors
– Four incoming 115 kV underground cables
– 115 kV open-air ring bus and equipment, with wall
bushings between rooms
– 12 kV is double-bus switchgear; multi-floor
– 15 radial feeders, 9 network feeders, 14 tie cables
– Three 50MVA and two 35MVA transformers,
forced-oil, in separated rooms
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Mission Substation Rebuild
External
Building
View
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Mission Substation Rebuild
Bank
Line
Bank
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Bank
Line
Bank
Bank
Existing Single Line Diagram – 9 element Ring Bus
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Mission Substation Rebuild
Existing
Control
Room
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Mission Substation Rebuild
• New Substation Configuration:
– Rebuild in place, rather than across the street
– Replace all existing 12 kV switchgear with new,
compact switchgear (frees up needed floor space)
– Increase capacity -- replace the 5 existing
transformers with new 75MVA standard size and add
a 6th transformer -- doubles capacity to 450 MVA!
– Reduce fault current levels -- only 2 banks in parallel
– Replace 115 kV open air bus with GIS
– Replace all relays and control with latest integrated
schemes
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Mission Substation Rebuild
Line
Line
FUT
Bank
Bank
Bank
Bank
Bank
Bank
FUT
Line
New Single Line Diagram – 6 bay BAAH (2 spare elements)
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Line
Mission Substation Rebuild
New
Control
Room
(simulated)
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Mission Substation Rebuild
• Conversion Timeline:
– 2007-2009 Switchgear
replacement, in two phases
– 2008 Award GIS and EPC
project contract
– 2010 Rebuild complete
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Q&A
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