California Energy Commission Staff Paper - April 12,20071 Estimating the Generation Resource Mix of Electricity Imports to California – Energy Commission

Staff Paper - April 12,2007 1

California Energy Commission

Estimating the Generation Resource Mix of Electricity Imports to California –

Energy Commission Staff Paper

California Energy Commission and Public Utilities CommissionWorkshop on Reporting and Tracking Greenhouse Gas Emissions for

a Load-Based Cap

April 12 and 13, 2007

Al Alvarado

Electricity Analysis Office

California Energy [email protected]



Presentation Overview

• Purpose of Resource Mix Analysis • Role of Electricity Imports • Average Regional Methodology• Alternative Approach to Estimate Resource

Mix



Goals of Resource Mix Analysis

• Increase attribution of specific purchases and ownership

• Estimate unspecified purchases into what is bought & sold in the market

• Advance links between statewide and LSE accounting

• Incremental improvement of current estimate, while shifting emphasis to new reporting and tracking



Types of Electricity Imports

• Ownership shares of generation located out-of-state

• Contracts and other entitlements• Purchases to satisfy customer obligations• Purchases to cover unexpected short-term

variations (i.e. forced outages)• Economy Purchases• Wheeling through CA



Average Methodology Used for GHG Emissions Imports Inventory

• 2000 to present GHG emission estimates apply the average generation mix in each region

• Current estimates reported in:– Net System Power Report– 2006 Greenhouse Emissions Inventory

Report



Limitations of Averaging Approach

• Does not account for specific ownership or power purchase agreements

• Ignores system constraints• Does not capture when and what types of

electricity is purchased• Assumes California is purchasing the same

mix as region’s native load• Does not account for other state’s priority

preferences



Revised Approach to Estimate Imports Resource Mix

• First identify ownership generation

• Identify long-term power purchase contracts and entitlements (i.e. Hoover)

• Remaining balance are considered unspecified system imports



Specified and Unspecified Imports by Region for 2005

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

Northwest Southwest

GW

h

Specified Unspecified

Unspecified

Specified



Estimating Sources of Unspecified Imports

• Separate Northwest and Southwest regions – different generation profiles

• Coordination with other western efforts• Initial study uses marginal generation

analysis for Southwest mix• Initial study uses marginal generation

analysis and sales assessment for Northwest



Rationale for Marginal Generation Analysis Used for Electricity System Imports

• Utilities and generators typically use their cheapest electricity supplies to meet customer obligations

• Baseload generation is usually the lower cost resource, mostly owned by utilities

• Remaining surplus are generally the marginal generation resources

• Electricity from marginal generation will be sold if there is a market



Southwest Study

• System simulations to respond to stakeholder questions on marginal resource assumptions

• Test to see what generation is re-dispatched with reduced imports

• Transfer capability reduced to amount needed for specified resources

• Transmission constraints create 53-59 GWH coal-generation drop (0.1%)

• Natural gas generation increase in CA & Southern Nevada, declines in rest of SW



Table 3 - 2005 Southwest Electricity Imports Resource Mix (GWh)

Resource Type Specified UnspecifiedUnspecified

PercentTotal

Percent mix

Coal 34,992 723 4% 35,715 57.4%

Nuclear 7,074 0 0% 7,074 11.4%

Hydropower 2,093 0 0% 2,093 3.4%

Natural Gas 0 17,360 96% 17,360 27.9%

Renewables 0 0 0% 0 0.0%

Total Imports 44,159 18,083 100% 62,242 100%

Percent Specified and Unspecified

71% 29% 100%



Unspecified Imports from Northwest

• NW predominately hydroelectric system

• High correlation between NW water conditions and California system imports

• Identify types of sellers to California

• Attribute generation mix to each seller:

– IOU, POU & Other = WA/OR disclosures

– Canada = Hydro

– IPP & Marketers = 50% Hydro, 46% Gas, 4% Coal



Table 5 - 2005 Northwest Electricity Imports Resource Mix (GWh)

Resource Type Specified UnspecifiedUnspecified

PercentTotal

Percent mix

Coal 565 1,572 8.8% 2,137 10.5%

Nuclear 161 305 1.7% 466 2.3%

Hydropower 1,432 11,811 66.0% 13,243 65.3%

Natural Gas 0 3,945 22.1% 3,945 19.4%

Renewables 237 249 1.4% 486 2.4%

Other 9 0 0% 9 0%

Total Imports 2,404 17,882 100% 20,286 100%

Percent Specified and Unspecified

12% 88% 100%



Comparison of the 2005 Total Statewide Imports Resource Mix Using the Revised and Average Estimation Methods

Resource Type Revised Method Average Method

Coal 45.9% 59.4%

Large Hydro 18.6% 18.2%

Natural Gas 25.8% 15.5%

Nuclear 9.1% 6.8%

Renewables 0.6% 0.0%

Total 100.0% 100.0%



Inter-State Coordination

• Working with Washington and Oregon energy staff

• Better understand purpose and tracking methodologies between states

• A coordinated regional tracking system is needed– Avoid double-counting and shifting emission

attributions– LSE transaction choices that lead to actual

emission reduction



Partial Data Available to Track Imports

• Metered gross and net power flows between 3 CA and out-of-state control area operators

• Electricity generation and fuel use by power plant• Power Source Disclosure for 70% of CA• FERC and EIA Reporting • Limited information on the generation source of the

electricity imports• Additional types of data needed to advance ability to

track transactions



Conclusion

• The revised methodology provides a more detailed characterization than previous approaches

• More LSE purchase data would refine the resource mix estimates

• This is an interim approach for historical and near-term tracking

• More policy analysis and inter-state discussion needed prior to finalizing methodology



Background Slides



Net Electricity Imports(MWh)

Region Year Q1 Q2 Q3 Q4 Annual total

PNW 2001 -364,132 1,475,615 2,242,620 3,472,131 6,826,234

2002 4,619,490 9,208,724 8,551,711 4,806,167 27,186,092

2003 4,482,276 7,534,088 5,992,730 4,294,350 22,303,444

2004 3,853,304 5,992,202 5,035,305 5,949,924 20,830,735

2005 3,997,021 5,731,711 7,064,845 3,492,107 20,285,684

SW 2001 15,349,535 12,742,718 11,124,858 14,387,373 53,604,483

2002 14,253,560 12,385,210 12,137,492 17,161,832 55,938,094

2003 15,249,402 12,576,501 14,764,951 16,264,781 58,855,634

2004 15,885,639 15,559,711 16,903,486 17,601,506 65,950,343

2005 15,851,577 12,815,954 15,582,760 17,934,369 62,184,661



Quarterly PNW & SWNet Electricity Imports

(2001-2005)

-5,000,000

0

5,000,000

10,000,000

15,000,000

20,000,000

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

2001 2002 2003 2004 2005

MW

h

PNW SW



Net System Power ReportImports from PNW and SW (GWh)

6833%1,766

9% 4,87224%

12,74164%

1,6734%

10,63125% 24,381

58%

5,48513%

CoalHydroNatural GasNuclear



2005 Net Electricity Imports (GWhs)

Import Type NW SW Total% of Total

Specified Imports 2,404 44,159 46,563 56%

Unspecified Imports 17,882 18,083 35,965 44%

Total Imports 20,286 62,242 82,528

Regional % 25% 75%

Source: California Energy Commission



Generation from CA Utility Ownership Shares (GWh per year)

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

2001 2002 2003 2004 2005

Year

GW

h

Palo Verde

San Juan

Reid Gardner

Navajo

Four Corners

Mohave

Intermountain



Facility Name Dependable Capacity (MW)

Ownership Shares

Percent MW

Intermountain 1,810 96.0% 1,738

Mohave 1,387 66.0% 915

Four Corners 2,140 34.6% 740

Navajo 2,250 21.2% 477

Reid Gardner 595 29.9% 178

San Juan 1,647 24.2% 399

Palo Verde 3,867 27.4% 1,060

Total 13,696 5,507

California Utility Ownership Shares of Generation Facilities Located Out-of-State

(Dependable Capacity MW)



Facility Name 2001 2002 2003 2004 2005

Intermountain 12,855 12,947 13,020 13,852 13,118

Mohave 6,766 6,712 6,401 6,715 6,954

Four Corners 5,211 4,468 5,425 5,171 5,403

Navajo 3,686 3,780 3,461 3,757 3,611

Reid Gardner 1,147 1,253 1,226 1,215 1,176

San Juan 2,863 3,000 2,743 3,024 3,016

Palo Verde 7,873 8,459 7,832 7,706 7,074

Total Generation 40,402 40,620 40,107 41,439 40,351

Generation from California Utility Ownership Shares(Gigawatt hours per year)



CA Utility Ownership of Out-of-State Plants (Summer Capacity MW)

* IPP figures represent contracted capacity.** Source: Global Energy Decisions

Owner NameBloomington

Power PL IPP*Four

Corners NavajoPalo

VerdeReid

Gardner San Juan YuccaYuma Axis

Grand Total

Anaheim 239.00 50.81 289.81Azusa 2.32 30.47 32.79Banning 2.32 20.31 22.64Burbank 62.00 10.07 72.07CA DWR 179.67 179.67Colton 2.32 30.47 32.79Glendale 30.00 10.07 20.31 60.39IID 14.73 105.52 95.00 22.00 237.25LADWP 1,189.00 477.00 374.32 2,040.32MID 72.63 72.63Pasadena 80.00 10.07 90.07Redding 21.81 21.81Riverside 138.00 12.40 150.40SVP 0.13 50.86 51.00SCE 710.40 612.25 1,322.65Vernon 11.24 11.24Grand Total 0.13 1,738.00 710.40 477.00 1,062.13 179.67 403.19 95.00 22.00 4,687.52



Correlation Between PNW Hydro-Generation and

Electricity Imports to California (1993-2005)

y = 0.175x - 13827

R2 = 0.6639

0

5,000

10,000

15,000

20,000

25,000

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140,000 160,000 180,000 200,000 220,000 240,000 260,000

PNW Hydro Generation

PN

W im

po

rts

to

Ca

lifo

rnia

(G

WH

)



2005 Statewide Electricity Imports Resource Mix (GWh)

Resource Type Specified Percent Mix UnspecifiedPercent

Mix Total Percent Mix

Coal 35,557 76% 2,295 6% 37,852 46%

Nuclear 7,235 16% 305 1% 7,540 9%

Hydropower 3,525 8% 11,811 33% 15,336 19%

Natural Gas 0 0% 21,305 59% 21,305 26%

Renewables 237 1% 249 1% 486 1%

Other 9 0% 0 0% 9 0%

Total 46,563 100% 35,965 100% 82,528 100%

Specified and Unspecified 56% 44% 100%

Documents

California Energy Commission Staff Paper - April 12,20071 Estimating the Generation Resource Mix of Electricity Imports to California – Energy Commission