1 7/25/2014

7/25/2014

Beth Musich

Director - Energy Markets & Capacity Products

Overview of Southern California

Gas / San Diego Gas & Electric

System Design & Operations

SoCalGas/SDG&E Gas Transmission

System with Electric Generation Plants

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SoCalGas/SDG&E Gas Transmission

System » 24,100 square mile service territory

» 24.3 million consumers, 6.6 million meters

» 3500 miles of transmission pipeline

» Designed to transport supply from fringes of service territory to primary load centers in Los Angeles and San Diego

» SoCalGas has provided service for more than 140 years Approximately 5% of total US market for natural gas

Throughput averages 1 trillion cubic feet per year

» SDG&E has provided service for more than 125 years Throughput averages 130 billion cubic feet per year

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System Capacity Design

» Designed to CPUC-mandated standards:

1-in-35 year peak day for core service

1-in-10 year peak day for firm noncore service

» Design capacity of 6.0 BCFD

Highest recorded demand: 5.3 BCFD in Dec.

1990

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Sources of Supply and Receipt Points

Zone Receipt Points Supply Source Capacity (MMCFD)

Northern North Needles, Topock, Kramer Junction

San Juan Basin, Rocky Mountain

1590

Southern Ehrenberg, Blythe, Otay Mesa

Permian Basin, LNG 1210

Wheeler Wheeler Ridge, Kern River Sta.

San Juan Basin, Rocky Mountain, Western Canada

765

California San Joaquin Valley, Coastal

Local 310

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3875 million cubic feet per day of firm receipt capacity

Storage Fields

» Four storage fields, located in southwest quadrant of service territory: 137.1 BCF of storage capacity

850 MMcfd of firm injection capacity

3195 MMcfd of firm withdrawal capacity

» Storage rights are allocated and sold on a system-wide basis Rights are not tied to a specific storage field

» Gas Control Department operates to maximize system-wide capacities

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Mainline Compressor Stations

» SoCalGas/SDG&E own and operate 13

mainline compressor stations with a

combined total of 142,000 horsepower

» Compressor stations are operated as

necessary to maintain system integrity

Move supplies to changing load centers

Increase system pressures

Balance gas entering and leaving the system

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Electric Generation in Southern

California

» The SoCalGas/SDG&E system serves

20,000 MW of electric generation from 79

individual power plants

246 BCF of average EG demand

Winter maximum of 1000 MMcfd (11/13/2013)

Summer maximum of 1835 MMcfd (8/13/2012)

» Power plants are primarily concentrated in

the Los Angeles and San Diego load centers

Newer power plants have also sited outside of the

LA basin

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Quick-Start Power Plants

» Recent requests for service to new natural gas power plants have included quick-start technology 0-100% demand in 10 min

0-50% demand in 9 min, 50-100% in 1 min

» If a power plant is on the end of the system, linepack in vicinity of the plant is more limited

» Sudden and rapid pipeline pressure loss can occur on quick-start units 40 psig drop over quick-start ramp not uncommon

Up to 70 psig drop in extreme situations

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Quick-Start vs Traditional Start-up Profile

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0.00%

20.00%

40.00%

60.00%

80.00%

100.00%

120.00%

0 20 40 60 80 100 120 140 160 180 200

Pe

rce

nt

Gas

Usa

ge (

%)

Time (Minutes)

Quick-Start Startup Profile

OTC Steam Generation Startup Profile

Pressure Drops from Quick-Start Plants

Can Be Much Greater than Traditional Facilities

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290.00

300.00

310.00

320.00

330.00

340.00

350.00

360.00

370.00

380.00

390.00

400.00

6 AM 7 AM 8 AM 9 AM 10 AM 11 AM 12 PM 1 PM 2 PM

Pre

ssu

re (p

sig

)

Time (Hours)

Pressure Surrounding Facility Morning Start

TraditionalOperations1 Quick-StartPlant3 Quick-StartPlants

320.00

330.00

340.00

350.00

360.00

370.00

380.00

390.00

400.00

410.00

3 PM 4 PM 5 PM 6 PM 7 PM 8 PM 9 PM

Pre

ssu

re (p

sig

)

Time (Hours)

Pressure Surrounding Facility Afternoon Start

TraditionalOperations1 Quick-StartPlant3 Quick-StartPlants

Summary

» The SoCalGas and SDG&E transmission

system is designed to handle up to 6

BCFD of natural gas load

» The system provides flexibility for our

customers, however some level of pipeline

supply is always needed – we cannot

operate solely from storage supplies

» Quick start EG plants are changing the

nature of gas use on our system

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