January 27, 2015

Presented to: NWPCC – GRAC Committee

Pumped Storage - The Proven Grid Scale Storage Solution

Presentation Agenda – Part 1

Variable Energy Resources Integration Challenges The Need for Grid Flexibility

Pumped Storage Overview Discussion of Technology Capital and O&M cost

elements Pacific NW potential sites

Three Interrelated Challenge Provision of Balancing Services How can wind variability be

managed in a reliable, efficient manner while recognizing the limits on the region’s hydro flexibility and the need for dependable capacity?

Oversupply How can high hydro/high

wind/limited load conditions be reliably and equitably managed?

System Flexibility How much is there now, how much

will be needed?

Bulk and Distributed Energy Storage Technologies

Pumped Storage Information & Characteristics

Grid harmonics

Grid faults / stability

ms s min

Renewables - intermittency

µs

Scheduling / economics / emissions

Transmission bottlenecks

hours days Power Quality Bridging Power Energy Management

Variable Speed & Ternary PS Units

Advanced Conventional PS Units

Conventional PS Units

Time scale

Equipment Response Time & Grid Benefits

Why Energy Storage? Attenuates generation volatility

and physical availability risks Aligns peak generation to peak

loads Reduces imbalance due to

scheduling challenges Moderates transmission

congestion and improves system reliability

Enables further penetration of variable generating resources

EPRI Energy Storage Technology Options Report 1020676, 2010

Current Landscape/Installed

Capacity

Energy Storage Technologies

Pumped Storage footprint in terms of batteries

Existing U.S. Pumped Storage Projects Proven and Prolific

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

-1500

-1000

-500

0

500

1000

1500

2000

0:00

0:

43

1:26

2:

09

2:52

3:

35

4:18

5:

01

5:44

6:

27

7:10

7:

53

8:36

9:

19

10:0

2 10

:45

11:2

8 12

:11

12:5

4 13

:37

14:2

0 15

:03

15:4

6 16

:29

17:1

2 17

:55

18:3

8 19

:21

20:0

4 20

:47

21:3

0 22

:13

22:5

6 23

:39

Meg

awat

ts

Meg

awat

ts

Bad Creek Jocassee Load

Pumped Storage Load Following, Balancing and Reserves

2000 MW of Inc and Dec Reserves

Flattening the Intermittent Demand Curve with Pumped Storage and Hydro

Pumped Storage Offsets Peak System Loads

Duke Energy CarolinasGeneration by Type

-2000

0

2000

4000

6000

8000

10000

12000

14000

12/11/06 12/12/06 12/13/06 12/14/06 12/15/06 12/16/06 12/17/06 12/18/06

Duke-Carolinas System mW Nuclear, Coal, & CT mW Total Hydro mW Total CT

Substantial Portfolio Optimization

Most significant capacity/ramping impacts will likely be seen in Southern CA (largest loads plus daily solar ramp)

CAISO’s market structure designed to spread impacts across grid, but local constraints must be addressed (e.g., transmission, capacity, oversupply)

CAISO’s – “Duck Curve”

Load, Wind, and Solar Profiles – Base Scenario

The Need for Flexibility

BPA Load and Thermal

Hydro and Wind

0

1000

2000

3000

4000

5000

6000

7000

8000

10/1

/12

18:0

0

10/2

/12

0:00

10/2

/12

6:00

10/2

/12

12:0

0

10/2

/12

18:0

0

Load

/Gen

erat

ion

(MW

)

BPA Load Wind

Hydro Thermal

Interchange

Historic BPA Demand Load and Wind Power 6,250 MW's Projected Wind Interconnection

Net Load of Tomorrow???

Simulated 1,600 MW Project “X” Pumped Storage Dispatch Schedule

-2,000

-1,500

-1,000

-500

0

500

1,000

1,500

2,000

Jun 3

Jun 4

Jun 5

Jun 6

Jun 7

Jun 8

Jun 9

Jun 10PS

Pum

p (-)

and

Gen

(+) i

n M

W

PS Pump (MW) PS Gen (MW)

Traditional Pumped Storage Dispatch with Rapid Response

Historic BPA Load, Simulated Approximately 6,000 MW Projected Wind Interconnection and FCRPS Re-Dispatch due to Pumped Storage

A System Operator’s Dream Come True!

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

Jun 3

Jun 4

Jun 5

Jun 6

Jun 7

Jun 8

Jun 9

Jun 10G

ener

atio

n an

d Lo

ad (M

W)

Original Load (MW)Wind Generation (MW)FCRPS Generation w/ no Pumped Storage (MW)FCRPS Generation w/ Pumped Storage

What is it? Efficient Energy Shifting Strategic Flexibility Grid Stability Services.

How does it work? During periods of low power

demand, water is pumped from the lower lake to the upper lake.

During high demand periods, water from the upper reservoir is passed through turbines to generate power.

Power settings can be adjusted rapidly to provide “ancillary services”.

Hydroelectric Pumped Storage

Key Differentiator: Pumped Storage is a System Operations/Transmission tool

Key Qualities of Modern Pumped Storage Facilities

Closed Loop – No On Stream Reservoirs High Round-Trip Efficiency – 80% + Significant Ramping Rates – 10

MW/sec + High Capacity – 500 MW - 1,300 MW High Energy – 6- to 12-hour ponds =

10,000+MWh Fast Response – Seconds to Minutes Incremental and Decremental

Reserves

Pump-Turbines – Three Modes of Operation

Future Pumped Storage - Dinorwig Plant Capabilities

Dinorwig Mode Change Times

• Fast mode changes and start-up times • High ramping rates – 15 MW/second per unit • 40,000 mode changes per year (any combo below) • 6 Hour reservoir capacity • Recognized need for high reliability and availability Spin Gen

Shut Down

Spin Pump Pump

Generate

<30s

<30s

<30s

<12s

<3m <3m

<3m <90s

6m 6m

6m 7m

Advantages of Single and Variable Speed Pumped Storage Units

Proven technology with multiple suppliers

Lower equipment cost by ~30%

Smaller powerhouse size Lower O&M costs Shorter project schedule

Single Speed Pump-Turbine

Wide head range operation

Flatter and higher generating performance curve

Regulation in pumping cycle ±20% in power

Wider generating operating range

Variable Speed Pump-Turbine

Snapshot of Pumped Storage Globally

-

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

Ocea

nia

Latin

Ame

rica

Russ

ia &

CIS

Midd

le Ea

st &

Afric

a

India

North

Ame

rica

China

Asia

w/o C

hina &

India

Euro

pe

Pump Storage Units in Operation (MW) by Country/Continent •127,961MW Worldwide •Totaling 922 PS Units

0 500 1000 1500 2000 2500

UNITED STATES

PORTUGAL

AUSTRIA

KOREA SOUTH

SPAIN

RUSSIA

SOUTH AFRICA

SWITZERLAND

JAPAN

CHINA

Pumped Storage Projects Under Construction (MW) •10,453 MW Worldwide •Totaling 45 PS Units

Proposed New Pumped Storage Projects

Study Project Name State Capacity (MW)

C-1 See Report, Large Number of Studies Nationwide N/A -----

C-2 John Day Pool WA 1300

C-2 Swan Lake OR 600

C-3 Crab Creek (varies by size) WA 69-392

C-3 Sand Hollow Creek WA 285

C-3 Hawk Creek (varies by size) WA 237-1136

C-3 Foster Creek WA 300-1100

C-4 John Day Pool (duplicate, also cited in C-2) WA -----

C-4 Swan Lake North OR 600

C-4 Brown’s Canyon WA 1000

C-4 Banks Lake Pumped Storage – North Banks Lake WA 1000

C-4 Banks Lake Pumped Storage – South Banks Lake WA 1040

C-4 Lorella (Klamath County) OR 1000

C-4 Gordon Butte MT 400

C-4 Yale-Merwin WA 255

Summary of Capacity Identified in Studies C-1 through C-4

Capital Cost Comparison

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1000

2000

3000

4000

5000

6000

7000

CAES (100 MW)

Lead-acid Battery (10 MW)

Pumped Storage (1000 MW)

Super Capacitor (100 MW)

Flywheel (100 MW)

Capi

tol C

ost (

$/kW

)

Comparison of Estimated Capital Cost in 2010 US $/kW- for Technologies Capable of 20 hrs of Storage or Longer

Note: Pumped Hydro and Pumped Hydro (Var Speed: O&M and Financed Capitol Cost are estimated by HDR|DTA. All other options are derived from data from Makarov, Y. et al. "Wide-Area Energy Storage and Management System to Balance Intermittent Resources in the Bonneville Power Administration and California ISO Control Areas." Table 3.2 .Pacific Northwest National Laboratory, June 2008.

NOTE: Costs presented are for

20 hours of energystorage

Life Cycle Costs - $/kW-yr

0

200

400

600

800

1000

1200

1400

1600

1800

Compressed Air Energy

Sources

Pumped Hydro Pumped Hydro (Var. Speed)

Regenesys Na/S Lead Acid Batteries

(flooded cell)

Lead-acid Battery (VRLA)

Zn/Br Ni/CD

Annu

al C

ost

($/k

W-y

r)

g ( g )

Financed Capital Cost Fuel Cost Electricity Cost O&M Cost Replacement Cost

Note: Pumped Hydro and Pumped Hydro (Var Speed : O&M and Financed Capitol Cost are estimated by HDR|DTA. All other options are derived from Schoenung, S. and Hassenzahl, "Long vs.. Short Term Energy Storage Technologies Analysis- A Life Cycle Cost" Sandia National Laboratories, Sandia Report August 2003.

Pumped Storage Economics

Licensing Cost Range up to $15 to $20 million

per license over the next 4 to 5 years

Installed Cost Range: $2,000 kW to $3,000 kW

($2 billion to $3 billion for a 1,000 MW facility)

O&M Costs: Fixed Costs Range: $10

million to $15 million/year Variable Cost Range:

~$1.00/MWh

31

California Pumped Storage Update

Iowa Hill – 400 MW

Eagle Mountain – 1400 MW