ETAAC

Energy Sector

Energy Storage------------------------

Smart Grid

July 12, 2007San Francisco, CA

2

Energy Storage• Electric energy storage goal of the industry

• Cost-effective energy storage would benefit all areas of the energy value chain: generation, transmission, distribution, and end-use

• Key applications: firming large penetration of intermittent renewables, grid support, end-use load shifting, etc.

• Current energy storage systems are only marginally cost competitive. Costs need to come down by factor of 2-5 times.

• Need innovation and standardization as well as policy recognition.

• California is best market for accelerating storage use due to technology base, clean energy emphasis (especially intermittent renewables), and leading-edge policies.

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Energy Storage Technologies

• Many different energy storage technologies are available for use in storage for renewable integration applications

Pumped Hydro Compressed Air Energy

Storage Lead-acid batteries Nickel-cadmium batteries

• Each technology has advantages and disadvantages• Not all of these technologies are appropriate for all

applications

Lithium ion batteries Sodium-Sulfur Batteries Flow Batteries Flywheels Ultracapacitors

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Uses of Energy Storage

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Balancing Function - Area Control

Hour Ahead Schedule

Incremental Energy

Decremental Energy

Day Ahead Schedule

Real Time Load

MW

Time

Real-Time Economic DispatchEvery 5 minutes

Upward Regulation

Ancillary Services• Regulation • Spinning Reserve • Non-Spinning

Reserve • Replacement

Reserve • Voltage Support• Black Start

capability

Ancillary Services• Regulation • Spinning Reserve • Non-Spinning

Reserve • Replacement

Reserve • Voltage Support• Black Start

capability

Downward Regulation

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Loads & Resources

Source: CEC PIER-funded study by GE Energy, July 2006

Temporal Pattern: July 2003 Average DayTemporal Pattern: July 2003 Average Day

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July 2006 Heat Wave – Peak Hours Wind Generation Energy Production

July 17:

(2:41 pm) 46,561 MW

July 21:

(4:28 pm) 49,036 MW

July 24:

(2:44 pm) 50,270 MW

New Records

Record

Time of Record Peaks

x

xx

Source: CAISO

Planned Capacity Level

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Need to Shift Some Wind Energy Production from Off-Peak to On-Peak

January 6, 2005 California Wind Generation

0

50

100

150

200

250

300

350

400

12:0

0 A

M

1:00

AM

2:00

AM

3:00

AM

4:00

AM

5:00

AM

6:00

AM

7:00

AM

8:00

AM

9:00

AM

10:0

0 A

M

11:0

0 A

M

12:0

0 P

M

1:00

PM

2:00

PM

3:00

PM

4:00

PM

5:00

PM

6:00

PM

7:00

PM

8:00

PM

9:00

PM

10:0

0 P

M

11:0

0 P

M

MW

TOTAL Pacheco Solano Tehachapi Altamont San Gorgonio

Maximum Energy Production at night

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Potential use of Flywheel Energy Storage for Area Control Error and Frequency Control

June 4, 2004

59.75

59.8

59.85

59.9

59.95

60

60.05

60.1

0:00

0:40

1:20

2:00

2:40

3:20

4:00

4:40

5:20

6:00

6:40

7:20

8:00

8:40

9:20

10:00

10:40

11:20

12:00

12:40

13:20

14:00

14:40

15:20

16:00

16:40

17:20

18:00

18:40

19:20

20:00

20:40

21:20

22:00

22:40

23:20 0:

00

Fre

qu

ency

-

Her

tz

-1500

-1000

-500

0

500

1000

1500

AC

E M

egaw

atts

Freq ACE

10

20

25

30

35

40

45

1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12

Sys

tem

Lo

ad (

GW

)

Typical Load

Load w/ 4 mil. PHEVs

Off-peak load

Off-peak load

Vehicle-to-grid energy

(V2G)

Vehicle-to-grid energy

(V2G)

Ancillary Services available when vehicles are parked

Ancillary Services available when vehicles are parked

AM PM

Plug Hybrid Electric Vehicles Complement Renewables

off-peak load off-peak load

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Dispatchability Option via Thermal Storage

Actual June dayActual June day

Actual September dayActual September day

Actual September day w/ supplemental gasActual September day w/ supplemental gas

Parabolic Trough Solar Technology for Utility Power Markets in the Southwestern United States, Henry Price, National Renewable Energy Laboratory, August 2004Parabolic Trough Solar Technology for Utility Power Markets in the Southwestern United States, Henry Price, National Renewable Energy Laboratory, August 2004

Solar thermal can add storage or to become more dispatchable.

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13

14

Next Gen

Li-ion?

Next Gen Flow

Battery?

15

16

17

18

Compressed Air Energy Storage (CAES)

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CAES Geology by State

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Lithium Ion Battery